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Stop the SSH panel appearing in PuTTYtel
[u/mdw/putty] / ssh.c
CommitLineData
374330e2 1#include <stdio.h>
2#include <stdlib.h>
fb09bf1c 3#include <stdarg.h>
4#include <assert.h>
4d331a77 5#ifndef AUTO_WINSOCK
6#ifdef WINSOCK_TWO
7#include <winsock2.h>
8#else
374330e2 9#include <winsock.h>
4d331a77 10#endif
11#endif
374330e2 12
13#include "putty.h"
dacbd0e8 14#include "tree234.h"
fb09bf1c 15#include "ssh.h"
374330e2 16
17#ifndef FALSE
18#define FALSE 0
19#endif
20#ifndef TRUE
21#define TRUE 1
22#endif
23
fb09bf1c 24#define logevent(s) { logevent(s); \
67779be7 25 if ((flags & FLAG_STDERR) && (flags & FLAG_VERBOSE)) \
fb09bf1c 26 fprintf(stderr, "%s\n", s); }
27
8d5de777 28#define bombout(msg) ( ssh_state == SSH_STATE_CLOSED, closesocket(s), \
29 s = INVALID_SOCKET, connection_fatal msg )
30
d211621f 31#define SSH1_MSG_DISCONNECT 1 /* 0x1 */
32#define SSH1_SMSG_PUBLIC_KEY 2 /* 0x2 */
33#define SSH1_CMSG_SESSION_KEY 3 /* 0x3 */
34#define SSH1_CMSG_USER 4 /* 0x4 */
35#define SSH1_CMSG_AUTH_RSA 6 /* 0x6 */
36#define SSH1_SMSG_AUTH_RSA_CHALLENGE 7 /* 0x7 */
37#define SSH1_CMSG_AUTH_RSA_RESPONSE 8 /* 0x8 */
38#define SSH1_CMSG_AUTH_PASSWORD 9 /* 0x9 */
39#define SSH1_CMSG_REQUEST_PTY 10 /* 0xa */
40#define SSH1_CMSG_WINDOW_SIZE 11 /* 0xb */
41#define SSH1_CMSG_EXEC_SHELL 12 /* 0xc */
42#define SSH1_CMSG_EXEC_CMD 13 /* 0xd */
43#define SSH1_SMSG_SUCCESS 14 /* 0xe */
44#define SSH1_SMSG_FAILURE 15 /* 0xf */
45#define SSH1_CMSG_STDIN_DATA 16 /* 0x10 */
46#define SSH1_SMSG_STDOUT_DATA 17 /* 0x11 */
47#define SSH1_SMSG_STDERR_DATA 18 /* 0x12 */
48#define SSH1_CMSG_EOF 19 /* 0x13 */
49#define SSH1_SMSG_EXIT_STATUS 20 /* 0x14 */
50#define SSH1_MSG_CHANNEL_OPEN_CONFIRMATION 21 /* 0x15 */
51#define SSH1_MSG_CHANNEL_OPEN_FAILURE 22 /* 0x16 */
52#define SSH1_MSG_CHANNEL_DATA 23 /* 0x17 */
53#define SSH1_MSG_CHANNEL_CLOSE 24 /* 0x18 */
54#define SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION 25 /* 0x19 */
55#define SSH1_CMSG_AGENT_REQUEST_FORWARDING 30 /* 0x1e */
56#define SSH1_SMSG_AGENT_OPEN 31 /* 0x1f */
57#define SSH1_CMSG_EXIT_CONFIRMATION 33 /* 0x21 */
58#define SSH1_MSG_IGNORE 32 /* 0x20 */
59#define SSH1_MSG_DEBUG 36 /* 0x24 */
60#define SSH1_CMSG_AUTH_TIS 39 /* 0x27 */
61#define SSH1_SMSG_AUTH_TIS_CHALLENGE 40 /* 0x28 */
62#define SSH1_CMSG_AUTH_TIS_RESPONSE 41 /* 0x29 */
63#define SSH1_CMSG_AUTH_CCARD 70 /* 0x46 */
64#define SSH1_SMSG_AUTH_CCARD_CHALLENGE 71 /* 0x47 */
65#define SSH1_CMSG_AUTH_CCARD_RESPONSE 72 /* 0x48 */
66
67#define SSH1_AUTH_TIS 5 /* 0x5 */
68#define SSH1_AUTH_CCARD 16 /* 0x10 */
69
70#define SSH_AGENTC_REQUEST_RSA_IDENTITIES 1 /* 0x1 */
71#define SSH_AGENT_RSA_IDENTITIES_ANSWER 2 /* 0x2 */
72#define SSH_AGENTC_RSA_CHALLENGE 3 /* 0x3 */
73#define SSH_AGENT_RSA_RESPONSE 4 /* 0x4 */
74#define SSH_AGENT_FAILURE 5 /* 0x5 */
75#define SSH_AGENT_SUCCESS 6 /* 0x6 */
76#define SSH_AGENTC_ADD_RSA_IDENTITY 7 /* 0x7 */
77#define SSH_AGENTC_REMOVE_RSA_IDENTITY 8 /* 0x8 */
78
79#define SSH2_MSG_DISCONNECT 1 /* 0x1 */
80#define SSH2_MSG_IGNORE 2 /* 0x2 */
81#define SSH2_MSG_UNIMPLEMENTED 3 /* 0x3 */
82#define SSH2_MSG_DEBUG 4 /* 0x4 */
83#define SSH2_MSG_SERVICE_REQUEST 5 /* 0x5 */
84#define SSH2_MSG_SERVICE_ACCEPT 6 /* 0x6 */
85#define SSH2_MSG_KEXINIT 20 /* 0x14 */
86#define SSH2_MSG_NEWKEYS 21 /* 0x15 */
87#define SSH2_MSG_KEXDH_INIT 30 /* 0x1e */
88#define SSH2_MSG_KEXDH_REPLY 31 /* 0x1f */
89#define SSH2_MSG_USERAUTH_REQUEST 50 /* 0x32 */
90#define SSH2_MSG_USERAUTH_FAILURE 51 /* 0x33 */
91#define SSH2_MSG_USERAUTH_SUCCESS 52 /* 0x34 */
92#define SSH2_MSG_USERAUTH_BANNER 53 /* 0x35 */
93#define SSH2_MSG_USERAUTH_PK_OK 60 /* 0x3c */
94#define SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ 60 /* 0x3c */
95#define SSH2_MSG_GLOBAL_REQUEST 80 /* 0x50 */
96#define SSH2_MSG_REQUEST_SUCCESS 81 /* 0x51 */
97#define SSH2_MSG_REQUEST_FAILURE 82 /* 0x52 */
98#define SSH2_MSG_CHANNEL_OPEN 90 /* 0x5a */
99#define SSH2_MSG_CHANNEL_OPEN_CONFIRMATION 91 /* 0x5b */
100#define SSH2_MSG_CHANNEL_OPEN_FAILURE 92 /* 0x5c */
101#define SSH2_MSG_CHANNEL_WINDOW_ADJUST 93 /* 0x5d */
102#define SSH2_MSG_CHANNEL_DATA 94 /* 0x5e */
103#define SSH2_MSG_CHANNEL_EXTENDED_DATA 95 /* 0x5f */
104#define SSH2_MSG_CHANNEL_EOF 96 /* 0x60 */
105#define SSH2_MSG_CHANNEL_CLOSE 97 /* 0x61 */
106#define SSH2_MSG_CHANNEL_REQUEST 98 /* 0x62 */
107#define SSH2_MSG_CHANNEL_SUCCESS 99 /* 0x63 */
108#define SSH2_MSG_CHANNEL_FAILURE 100 /* 0x64 */
109
110#define SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED 1 /* 0x1 */
111#define SSH2_OPEN_CONNECT_FAILED 2 /* 0x2 */
112#define SSH2_OPEN_UNKNOWN_CHANNEL_TYPE 3 /* 0x3 */
113#define SSH2_OPEN_RESOURCE_SHORTAGE 4 /* 0x4 */
114
115#define SSH2_EXTENDED_DATA_STDERR 1 /* 0x1 */
fb09bf1c 116
117#define GET_32BIT(cp) \
118 (((unsigned long)(unsigned char)(cp)[0] << 24) | \
119 ((unsigned long)(unsigned char)(cp)[1] << 16) | \
120 ((unsigned long)(unsigned char)(cp)[2] << 8) | \
121 ((unsigned long)(unsigned char)(cp)[3]))
122
123#define PUT_32BIT(cp, value) { \
124 (cp)[0] = (unsigned char)((value) >> 24); \
125 (cp)[1] = (unsigned char)((value) >> 16); \
126 (cp)[2] = (unsigned char)((value) >> 8); \
127 (cp)[3] = (unsigned char)(value); }
128
7cca0d81 129enum { PKT_END, PKT_INT, PKT_CHAR, PKT_DATA, PKT_STR, PKT_BIGNUM };
972a41c8 130
374330e2 131/* Coroutine mechanics for the sillier bits of the code */
132#define crBegin1 static int crLine = 0;
133#define crBegin2 switch(crLine) { case 0:;
134#define crBegin crBegin1; crBegin2;
135#define crFinish(z) } crLine = 0; return (z)
136#define crFinishV } crLine = 0; return
137#define crReturn(z) \
138 do {\
139 crLine=__LINE__; return (z); case __LINE__:;\
140 } while (0)
141#define crReturnV \
142 do {\
143 crLine=__LINE__; return; case __LINE__:;\
144 } while (0)
145#define crStop(z) do{ crLine = 0; return (z); }while(0)
146#define crStopV do{ crLine = 0; return; }while(0)
fb09bf1c 147#define crWaitUntil(c) do { crReturn(0); } while (!(c))
7cca0d81 148#define crWaitUntilV(c) do { crReturnV; } while (!(c))
374330e2 149
57476f6b 150extern const struct ssh_cipher ssh_3des;
151extern const struct ssh_cipher ssh_3des_ssh2;
152extern const struct ssh_cipher ssh_des;
153extern const struct ssh_cipher ssh_blowfish_ssh1;
154extern const struct ssh_cipher ssh_blowfish_ssh2;
e5574168 155
5e8358ad 156/*
157 * Ciphers for SSH2. We miss out single-DES because it isn't
158 * supported; also 3DES and Blowfish are both done differently from
159 * SSH1. (3DES uses outer chaining; Blowfish has the opposite
160 * endianness and different-sized keys.)
5e8358ad 161 */
57476f6b 162const static struct ssh_cipher *ciphers[] = { &ssh_blowfish_ssh2, &ssh_3des_ssh2 };
e5574168 163
57476f6b 164extern const struct ssh_kex ssh_diffiehellman;
165const static struct ssh_kex *kex_algs[] = { &ssh_diffiehellman };
e5574168 166
57476f6b 167extern const struct ssh_hostkey ssh_dss;
168const static struct ssh_hostkey *hostkey_algs[] = { &ssh_dss };
e5574168 169
57476f6b 170extern const struct ssh_mac ssh_sha1;
e5574168 171
d39f364a 172static void nullmac_key(unsigned char *key) { }
e5574168 173static void nullmac_generate(unsigned char *blk, int len, unsigned long seq) { }
174static int nullmac_verify(unsigned char *blk, int len, unsigned long seq) { return 1; }
57476f6b 175const static struct ssh_mac ssh_mac_none = {
d39f364a 176 nullmac_key, nullmac_key, nullmac_generate, nullmac_verify, "none", 0
e5574168 177};
57476f6b 178const static struct ssh_mac *macs[] = { &ssh_sha1, &ssh_mac_none };
e5574168 179
57476f6b 180const static struct ssh_compress ssh_comp_none = {
e5574168 181 "none"
182};
57476f6b 183const static struct ssh_compress *compressions[] = { &ssh_comp_none };
374330e2 184
dacbd0e8 185/*
186 * 2-3-4 tree storing channels.
187 */
188struct ssh_channel {
d211621f 189 unsigned remoteid, localid;
dacbd0e8 190 int type;
191 int closes;
192 union {
193 struct ssh_agent_channel {
194 unsigned char *message;
195 unsigned char msglen[4];
196 int lensofar, totallen;
197 } a;
d211621f 198 struct ssh2_data_channel {
199 unsigned char *outbuffer;
200 unsigned outbuflen, outbufsize;
201 unsigned remwindow, remmaxpkt;
202 } v2;
dacbd0e8 203 } u;
204};
57476f6b 205
206struct Packet {
207 long length;
208 int type;
209 unsigned char *data;
210 unsigned char *body;
211 long savedpos;
212 long maxlen;
213};
214
215static SHA_State exhash;
216
217static SOCKET s = INVALID_SOCKET;
218
219static unsigned char session_key[32];
220static const struct ssh_cipher *cipher = NULL;
221static const struct ssh_cipher *cscipher = NULL;
222static const struct ssh_cipher *sccipher = NULL;
223static const struct ssh_mac *csmac = NULL;
224static const struct ssh_mac *scmac = NULL;
225static const struct ssh_compress *cscomp = NULL;
226static const struct ssh_compress *sccomp = NULL;
227static const struct ssh_kex *kex = NULL;
228static const struct ssh_hostkey *hostkey = NULL;
229int (*ssh_get_password)(const char *prompt, char *str, int maxlen) = NULL;
230
231static char *savedhost;
232static int savedport;
233static int ssh_send_ok;
234
dacbd0e8 235static tree234 *ssh_channels; /* indexed by local id */
57476f6b 236static struct ssh_channel *mainchan; /* primary session channel */
237
238static enum {
239 SSH_STATE_BEFORE_SIZE,
240 SSH_STATE_INTERMED,
241 SSH_STATE_SESSION,
242 SSH_STATE_CLOSED
243} ssh_state = SSH_STATE_BEFORE_SIZE;
244
245static int size_needed = FALSE;
246
247static struct Packet pktin = { 0, 0, NULL, NULL, 0 };
248static struct Packet pktout = { 0, 0, NULL, NULL, 0 };
249
250static int ssh_version;
251static void (*ssh_protocol)(unsigned char *in, int inlen, int ispkt);
252static void ssh1_protocol(unsigned char *in, int inlen, int ispkt);
253static void ssh2_protocol(unsigned char *in, int inlen, int ispkt);
254static void ssh_size(void);
255
256static int (*s_rdpkt)(unsigned char **data, int *datalen);
257
258static struct rdpkt1_state_tag {
259 long len, pad, biglen, to_read;
260 unsigned long realcrc, gotcrc;
261 unsigned char *p;
262 int i;
263 int chunk;
264} rdpkt1_state;
265
960e736a 266static struct rdpkt2_state_tag {
267 long len, pad, payload, packetlen, maclen;
268 int i;
269 int cipherblk;
270 unsigned long incoming_sequence;
271} rdpkt2_state;
272
dacbd0e8 273static int ssh_channelcmp(void *av, void *bv) {
274 struct ssh_channel *a = (struct ssh_channel *)av;
275 struct ssh_channel *b = (struct ssh_channel *)bv;
276 if (a->localid < b->localid) return -1;
277 if (a->localid > b->localid) return +1;
278 return 0;
279}
280static int ssh_channelfind(void *av, void *bv) {
d211621f 281 unsigned *a = (unsigned *)av;
dacbd0e8 282 struct ssh_channel *b = (struct ssh_channel *)bv;
283 if (*a < b->localid) return -1;
284 if (*a > b->localid) return +1;
285 return 0;
286}
287
374330e2 288static void s_write (char *buf, int len) {
289 while (len > 0) {
290 int i = send (s, buf, len, 0);
4017be6d 291 noise_ultralight(i);
8d5de777 292 if (i <= 0) {
293 bombout(("Lost connection while sending"));
294 return;
295 }
374330e2 296 if (i > 0)
297 len -= i, buf += i;
298 }
299}
300
301static int s_read (char *buf, int len) {
302 int ret = 0;
303 while (len > 0) {
304 int i = recv (s, buf, len, 0);
4017be6d 305 noise_ultralight(i);
374330e2 306 if (i > 0)
307 len -= i, buf += i, ret += i;
308 else
309 return i;
310 }
311 return ret;
312}
313
314static void c_write (char *buf, int len) {
67779be7 315 if ((flags & FLAG_STDERR)) {
4017be6d 316 int i;
317 for (i = 0; i < len; i++)
318 if (buf[i] != '\r')
319 fputc(buf[i], stderr);
fb09bf1c 320 return;
321 }
c9def1b8 322 while (len--)
323 c_write1(*buf++);
374330e2 324}
325
3bdaf79d 326static void c_writedata (char *buf, int len) {
327 while (len--)
328 c_write1(*buf++);
329}
330
fb09bf1c 331/*
332 * Collect incoming data in the incoming packet buffer.
e5574168 333 * Decipher and verify the packet when it is completely read.
334 * Drop SSH1_MSG_DEBUG and SSH1_MSG_IGNORE packets.
fb09bf1c 335 * Update the *data and *datalen variables.
336 * Return the additional nr of bytes needed, or 0 when
337 * a complete packet is available.
338 */
e5574168 339static int ssh1_rdpkt(unsigned char **data, int *datalen)
fb09bf1c 340{
57476f6b 341 struct rdpkt1_state_tag *st = &rdpkt1_state;
374330e2 342
343 crBegin;
374330e2 344
fb09bf1c 345next_packet:
37508af4 346
fb09bf1c 347 pktin.type = 0;
348 pktin.length = 0;
374330e2 349
57476f6b 350 for (st->i = st->len = 0; st->i < 4; st->i++) {
fb09bf1c 351 while ((*datalen) == 0)
57476f6b 352 crReturn(4-st->i);
353 st->len = (st->len << 8) + **data;
fb09bf1c 354 (*data)++, (*datalen)--;
355 }
374330e2 356
fb09bf1c 357#ifdef FWHACK
57476f6b 358 if (st->len == 0x52656d6f) { /* "Remo"te server has closed ... */
359 st->len = 0x300; /* big enough to carry to end */
fb09bf1c 360 }
361#endif
374330e2 362
57476f6b 363 st->pad = 8 - (st->len % 8);
364 st->biglen = st->len + st->pad;
365 pktin.length = st->len - 5;
fb09bf1c 366
57476f6b 367 if (pktin.maxlen < st->biglen) {
368 pktin.maxlen = st->biglen;
369 pktin.data = (pktin.data == NULL ? malloc(st->biglen+APIEXTRA) :
370 realloc(pktin.data, st->biglen+APIEXTRA));
fb09bf1c 371 if (!pktin.data)
372 fatalbox("Out of memory");
373 }
374330e2 374
57476f6b 375 st->to_read = st->biglen;
376 st->p = pktin.data;
377 while (st->to_read > 0) {
378 st->chunk = st->to_read;
fb09bf1c 379 while ((*datalen) == 0)
57476f6b 380 crReturn(st->to_read);
381 if (st->chunk > (*datalen))
382 st->chunk = (*datalen);
383 memcpy(st->p, *data, st->chunk);
384 *data += st->chunk;
385 *datalen -= st->chunk;
386 st->p += st->chunk;
387 st->to_read -= st->chunk;
fb09bf1c 388 }
374330e2 389
fb09bf1c 390 if (cipher)
57476f6b 391 cipher->decrypt(pktin.data, st->biglen);
374330e2 392
57476f6b 393 pktin.type = pktin.data[st->pad];
394 pktin.body = pktin.data + st->pad + 1;
374330e2 395
57476f6b 396 st->realcrc = crc32(pktin.data, st->biglen-4);
397 st->gotcrc = GET_32BIT(pktin.data+st->biglen-4);
398 if (st->gotcrc != st->realcrc) {
8d5de777 399 bombout(("Incorrect CRC received on packet"));
400 crReturn(0);
fb09bf1c 401 }
572f871e 402
e5574168 403 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
404 pktin.type == SSH1_SMSG_STDERR_DATA ||
405 pktin.type == SSH1_MSG_DEBUG ||
18515c51 406 pktin.type == SSH1_SMSG_AUTH_TIS_CHALLENGE ||
407 pktin.type == SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
fb09bf1c 408 long strlen = GET_32BIT(pktin.body);
8d5de777 409 if (strlen + 4 != pktin.length) {
410 bombout(("Received data packet with bogus string length"));
411 crReturn(0);
412 }
fb09bf1c 413 }
414
e5574168 415 if (pktin.type == SSH1_MSG_DEBUG) {
fb09bf1c 416 /* log debug message */
417 char buf[80];
418 int strlen = GET_32BIT(pktin.body);
419 strcpy(buf, "Remote: ");
420 if (strlen > 70) strlen = 70;
421 memcpy(buf+8, pktin.body+4, strlen);
422 buf[8+strlen] = '\0';
423 logevent(buf);
424 goto next_packet;
e5574168 425 } else if (pktin.type == SSH1_MSG_IGNORE) {
fb09bf1c 426 /* do nothing */
427 goto next_packet;
428 }
429
430 crFinish(0);
431}
432
e5574168 433static int ssh2_rdpkt(unsigned char **data, int *datalen)
434{
960e736a 435 struct rdpkt2_state_tag *st = &rdpkt2_state;
e5574168 436
437 crBegin;
438
439next_packet:
e5574168 440 pktin.type = 0;
441 pktin.length = 0;
960e736a 442 if (sccipher)
443 st->cipherblk = sccipher->blksize;
e5574168 444 else
960e736a 445 st->cipherblk = 8;
446 if (st->cipherblk < 8)
447 st->cipherblk = 8;
448
449 if (pktin.maxlen < st->cipherblk) {
450 pktin.maxlen = st->cipherblk;
451 pktin.data = (pktin.data == NULL ? malloc(st->cipherblk+APIEXTRA) :
452 realloc(pktin.data, st->cipherblk+APIEXTRA));
e5574168 453 if (!pktin.data)
454 fatalbox("Out of memory");
455 }
456
457 /*
458 * Acquire and decrypt the first block of the packet. This will
459 * contain the length and padding details.
460 */
960e736a 461 for (st->i = st->len = 0; st->i < st->cipherblk; st->i++) {
e5574168 462 while ((*datalen) == 0)
960e736a 463 crReturn(st->cipherblk-st->i);
464 pktin.data[st->i] = *(*data)++;
e5574168 465 (*datalen)--;
466 }
467#ifdef FWHACK
468 if (!memcmp(pktin.data, "Remo", 4)) {/* "Remo"te server has closed ... */
469 /* FIXME */
470 }
471#endif
472 if (sccipher)
960e736a 473 sccipher->decrypt(pktin.data, st->cipherblk);
e5574168 474
475 /*
476 * Now get the length and padding figures.
477 */
960e736a 478 st->len = GET_32BIT(pktin.data);
479 st->pad = pktin.data[4];
e5574168 480
481 /*
482 * This enables us to deduce the payload length.
483 */
960e736a 484 st->payload = st->len - st->pad - 1;
e5574168 485
960e736a 486 pktin.length = st->payload + 5;
e5574168 487
488 /*
489 * So now we can work out the total packet length.
490 */
960e736a 491 st->packetlen = st->len + 4;
492 st->maclen = scmac ? scmac->len : 0;
e5574168 493
494 /*
495 * Adjust memory allocation if packet is too big.
496 */
960e736a 497 if (pktin.maxlen < st->packetlen+st->maclen) {
498 pktin.maxlen = st->packetlen+st->maclen;
59dcd2a8 499 pktin.data = (pktin.data == NULL ? malloc(pktin.maxlen+APIEXTRA) :
500 realloc(pktin.data, pktin.maxlen+APIEXTRA));
e5574168 501 if (!pktin.data)
502 fatalbox("Out of memory");
503 }
504
505 /*
506 * Read and decrypt the remainder of the packet.
507 */
960e736a 508 for (st->i = st->cipherblk; st->i < st->packetlen + st->maclen; st->i++) {
e5574168 509 while ((*datalen) == 0)
960e736a 510 crReturn(st->packetlen + st->maclen - st->i);
511 pktin.data[st->i] = *(*data)++;
e5574168 512 (*datalen)--;
513 }
514 /* Decrypt everything _except_ the MAC. */
515 if (sccipher)
960e736a 516 sccipher->decrypt(pktin.data + st->cipherblk,
517 st->packetlen - st->cipherblk);
e5574168 518
7cca0d81 519#if 0
960e736a 520 debug(("Got packet len=%d pad=%d\r\n", st->len, st->pad));
521 for (st->i = 0; st->i < st->packetlen; st->i++)
522 debug((" %02x", (unsigned char)pktin.data[st->i]));
d39f364a 523 debug(("\r\n"));
7cca0d81 524#endif
d39f364a 525
e5574168 526 /*
527 * Check the MAC.
528 */
960e736a 529 if (scmac && !scmac->verify(pktin.data, st->len+4, st->incoming_sequence)) {
8d5de777 530 bombout(("Incorrect MAC received on packet"));
531 crReturn(0);
532 }
960e736a 533 st->incoming_sequence++; /* whether or not we MACed */
e5574168 534
535 pktin.savedpos = 6;
536 pktin.type = pktin.data[5];
e5574168 537
7cca0d81 538 if (pktin.type == SSH2_MSG_IGNORE || pktin.type == SSH2_MSG_DEBUG)
539 goto next_packet; /* FIXME: print DEBUG message */
e5574168 540
541 crFinish(0);
542}
543
fb09bf1c 544static void ssh_gotdata(unsigned char *data, int datalen)
545{
546 while (datalen > 0) {
85ee8208 547 if ( s_rdpkt(&data, &datalen) == 0 ) {
374330e2 548 ssh_protocol(NULL, 0, 1);
85ee8208 549 if (ssh_state == SSH_STATE_CLOSED) {
550 return;
551 }
552 }
374330e2 553 }
374330e2 554}
555
fb09bf1c 556
374330e2 557static void s_wrpkt_start(int type, int len) {
558 int pad, biglen;
559
560 len += 5; /* type and CRC */
561 pad = 8 - (len%8);
562 biglen = len + pad;
563
564 pktout.length = len-5;
565 if (pktout.maxlen < biglen) {
566 pktout.maxlen = biglen;
8f203108 567#ifdef MSCRYPTOAPI
fb09bf1c 568 /* Allocate enough buffer space for extra block
8f203108 569 * for MS CryptEncrypt() */
fb09bf1c 570 pktout.data = (pktout.data == NULL ? malloc(biglen+12) :
571 realloc(pktout.data, biglen+12));
8f203108 572#else
c1f5f956 573 pktout.data = (pktout.data == NULL ? malloc(biglen+4) :
574 realloc(pktout.data, biglen+4));
8f203108 575#endif
374330e2 576 if (!pktout.data)
577 fatalbox("Out of memory");
578 }
579
580 pktout.type = type;
581 pktout.body = pktout.data+4+pad+1;
582}
583
584static void s_wrpkt(void) {
585 int pad, len, biglen, i;
586 unsigned long crc;
587
588 len = pktout.length + 5; /* type and CRC */
589 pad = 8 - (len%8);
590 biglen = len + pad;
591
592 pktout.body[-1] = pktout.type;
593 for (i=0; i<pad; i++)
594 pktout.data[i+4] = random_byte();
595 crc = crc32(pktout.data+4, biglen-4);
fb09bf1c 596 PUT_32BIT(pktout.data+biglen, crc);
597 PUT_32BIT(pktout.data, len);
374330e2 598
599 if (cipher)
600 cipher->encrypt(pktout.data+4, biglen);
601
602 s_write(pktout.data, biglen+4);
603}
604
fb09bf1c 605/*
606 * Construct a packet with the specified contents and
607 * send it to the server.
608 */
609static void send_packet(int pkttype, ...)
610{
611 va_list args;
612 unsigned char *p, *argp, argchar;
613 unsigned long argint;
614 int pktlen, argtype, arglen;
7cca0d81 615 Bignum bn;
fb09bf1c 616
617 pktlen = 0;
618 va_start(args, pkttype);
619 while ((argtype = va_arg(args, int)) != PKT_END) {
620 switch (argtype) {
621 case PKT_INT:
622 (void) va_arg(args, int);
623 pktlen += 4;
624 break;
625 case PKT_CHAR:
626 (void) va_arg(args, char);
627 pktlen++;
628 break;
629 case PKT_DATA:
630 (void) va_arg(args, unsigned char *);
631 arglen = va_arg(args, int);
632 pktlen += arglen;
633 break;
634 case PKT_STR:
635 argp = va_arg(args, unsigned char *);
636 arglen = strlen(argp);
637 pktlen += 4 + arglen;
638 break;
7cca0d81 639 case PKT_BIGNUM:
640 bn = va_arg(args, Bignum);
5c58ad2d 641 pktlen += ssh1_bignum_length(bn);
7cca0d81 642 break;
fb09bf1c 643 default:
644 assert(0);
645 }
646 }
647 va_end(args);
648
649 s_wrpkt_start(pkttype, pktlen);
650 p = pktout.body;
651
652 va_start(args, pkttype);
653 while ((argtype = va_arg(args, int)) != PKT_END) {
654 switch (argtype) {
655 case PKT_INT:
656 argint = va_arg(args, int);
657 PUT_32BIT(p, argint);
658 p += 4;
659 break;
660 case PKT_CHAR:
661 argchar = va_arg(args, unsigned char);
662 *p = argchar;
663 p++;
664 break;
665 case PKT_DATA:
666 argp = va_arg(args, unsigned char *);
667 arglen = va_arg(args, int);
668 memcpy(p, argp, arglen);
669 p += arglen;
670 break;
671 case PKT_STR:
672 argp = va_arg(args, unsigned char *);
673 arglen = strlen(argp);
674 PUT_32BIT(p, arglen);
675 memcpy(p + 4, argp, arglen);
676 p += 4 + arglen;
677 break;
7cca0d81 678 case PKT_BIGNUM:
679 bn = va_arg(args, Bignum);
5c58ad2d 680 p += ssh1_write_bignum(p, bn);
7cca0d81 681 break;
fb09bf1c 682 }
683 }
684 va_end(args);
685
686 s_wrpkt();
687}
688
689
690/*
691 * Connect to specified host and port.
692 * Returns an error message, or NULL on success.
693 * Also places the canonical host name into `realhost'.
694 */
695static char *connect_to_host(char *host, int port, char **realhost)
696{
697 SOCKADDR_IN addr;
698 struct hostent *h;
699 unsigned long a;
700#ifdef FWHACK
701 char *FWhost;
702 int FWport;
703#endif
704
705 savedhost = malloc(1+strlen(host));
706 if (!savedhost)
707 fatalbox("Out of memory");
708 strcpy(savedhost, host);
709
710 if (port < 0)
711 port = 22; /* default ssh port */
d4857987 712 savedport = port;
fb09bf1c 713
714#ifdef FWHACK
715 FWhost = host;
716 FWport = port;
717 host = FWSTR;
718 port = 23;
719#endif
720
721 /*
722 * Try to find host.
723 */
724 if ( (a = inet_addr(host)) == (unsigned long) INADDR_NONE) {
725 if ( (h = gethostbyname(host)) == NULL)
726 switch (WSAGetLastError()) {
727 case WSAENETDOWN: return "Network is down";
728 case WSAHOST_NOT_FOUND: case WSANO_DATA:
729 return "Host does not exist";
730 case WSATRY_AGAIN: return "Host not found";
731 default: return "gethostbyname: unknown error";
732 }
733 memcpy (&a, h->h_addr, sizeof(a));
734 *realhost = h->h_name;
735 } else
736 *realhost = host;
737#ifdef FWHACK
738 *realhost = FWhost;
739#endif
740 a = ntohl(a);
741
742 /*
743 * Open socket.
744 */
745 s = socket(AF_INET, SOCK_STREAM, 0);
746 if (s == INVALID_SOCKET)
747 switch (WSAGetLastError()) {
748 case WSAENETDOWN: return "Network is down";
749 case WSAEAFNOSUPPORT: return "TCP/IP support not present";
750 default: return "socket(): unknown error";
751 }
752
753 /*
754 * Bind to local address.
755 */
756 addr.sin_family = AF_INET;
757 addr.sin_addr.s_addr = htonl(INADDR_ANY);
758 addr.sin_port = htons(0);
759 if (bind (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
760 switch (WSAGetLastError()) {
761 case WSAENETDOWN: return "Network is down";
762 default: return "bind(): unknown error";
763 }
764
765 /*
766 * Connect to remote address.
767 */
768 addr.sin_addr.s_addr = htonl(a);
769 addr.sin_port = htons((short)port);
770 if (connect (s, (struct sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR)
771 switch (WSAGetLastError()) {
772 case WSAENETDOWN: return "Network is down";
773 case WSAECONNREFUSED: return "Connection refused";
774 case WSAENETUNREACH: return "Network is unreachable";
775 case WSAEHOSTUNREACH: return "No route to host";
776 default: return "connect(): unknown error";
777 }
778
779#ifdef FWHACK
780 send(s, "connect ", 8, 0);
781 send(s, FWhost, strlen(FWhost), 0);
782 {
783 char buf[20];
784 sprintf(buf, " %d\n", FWport);
785 send (s, buf, strlen(buf), 0);
786 }
787#endif
788
789 return NULL;
790}
791
9697bfd2 792static int ssh_versioncmp(char *a, char *b) {
793 char *ae, *be;
794 unsigned long av, bv;
795
43aa02a7 796 av = strtoul(a, &ae, 10);
797 bv = strtoul(b, &be, 10);
9697bfd2 798 if (av != bv) return (av < bv ? -1 : +1);
799 if (*ae == '.') ae++;
800 if (*be == '.') be++;
43aa02a7 801 av = strtoul(ae, &ae, 10);
802 bv = strtoul(be, &be, 10);
9697bfd2 803 if (av != bv) return (av < bv ? -1 : +1);
804 return 0;
805}
806
e5574168 807
808/*
809 * Utility routine for putting an SSH-protocol `string' into a SHA
810 * state.
811 */
812#include <stdio.h>
75cab814 813static void sha_string(SHA_State *s, void *str, int len) {
e5574168 814 unsigned char lenblk[4];
e5574168 815 PUT_32BIT(lenblk, len);
e5574168 816 SHA_Bytes(s, lenblk, 4);
e5574168 817 SHA_Bytes(s, str, len);
818}
819
7cca0d81 820/*
821 * SSH2 packet construction functions.
822 */
75cab814 823static void ssh2_pkt_adddata(void *data, int len) {
7cca0d81 824 pktout.length += len;
825 if (pktout.maxlen < pktout.length) {
826 pktout.maxlen = pktout.length + 256;
827 pktout.data = (pktout.data == NULL ? malloc(pktout.maxlen+APIEXTRA) :
828 realloc(pktout.data, pktout.maxlen+APIEXTRA));
829 if (!pktout.data)
830 fatalbox("Out of memory");
831 }
832 memcpy(pktout.data+pktout.length-len, data, len);
833}
75cab814 834static void ssh2_pkt_addbyte(unsigned char byte) {
7cca0d81 835 ssh2_pkt_adddata(&byte, 1);
836}
75cab814 837static void ssh2_pkt_init(int pkt_type) {
7cca0d81 838 pktout.length = 5;
839 ssh2_pkt_addbyte((unsigned char)pkt_type);
840}
75cab814 841static void ssh2_pkt_addbool(unsigned char value) {
7cca0d81 842 ssh2_pkt_adddata(&value, 1);
843}
75cab814 844static void ssh2_pkt_adduint32(unsigned long value) {
7cca0d81 845 unsigned char x[4];
846 PUT_32BIT(x, value);
847 ssh2_pkt_adddata(x, 4);
848}
75cab814 849static void ssh2_pkt_addstring_start(void) {
7cca0d81 850 ssh2_pkt_adduint32(0);
851 pktout.savedpos = pktout.length;
852}
75cab814 853static void ssh2_pkt_addstring_str(char *data) {
7cca0d81 854 ssh2_pkt_adddata(data, strlen(data));
855 PUT_32BIT(pktout.data + pktout.savedpos - 4,
856 pktout.length - pktout.savedpos);
857}
75cab814 858static void ssh2_pkt_addstring_data(char *data, int len) {
7cca0d81 859 ssh2_pkt_adddata(data, len);
860 PUT_32BIT(pktout.data + pktout.savedpos - 4,
861 pktout.length - pktout.savedpos);
862}
75cab814 863static void ssh2_pkt_addstring(char *data) {
7cca0d81 864 ssh2_pkt_addstring_start();
865 ssh2_pkt_addstring_str(data);
866}
75cab814 867static char *ssh2_mpint_fmt(Bignum b, int *len) {
7cca0d81 868 unsigned char *p;
869 int i, n = b[0];
870 p = malloc(n * 2 + 1);
871 if (!p)
872 fatalbox("out of memory");
873 p[0] = 0;
874 for (i = 0; i < n; i++) {
875 p[i*2+1] = (b[n-i] >> 8) & 0xFF;
876 p[i*2+2] = (b[n-i] ) & 0xFF;
877 }
878 i = 0;
879 while (p[i] == 0 && (p[i+1] & 0x80) == 0)
880 i++;
881 memmove(p, p+i, n*2+1-i);
882 *len = n*2+1-i;
883 return p;
884}
75cab814 885static void ssh2_pkt_addmp(Bignum b) {
7cca0d81 886 unsigned char *p;
887 int len;
888 p = ssh2_mpint_fmt(b, &len);
889 ssh2_pkt_addstring_start();
890 ssh2_pkt_addstring_data(p, len);
891 free(p);
892}
75cab814 893static void ssh2_pkt_send(void) {
7cca0d81 894 int cipherblk, maclen, padding, i;
895 static unsigned long outgoing_sequence = 0;
896
897 /*
898 * Add padding. At least four bytes, and must also bring total
899 * length (minus MAC) up to a multiple of the block size.
900 */
901 cipherblk = cipher ? cipher->blksize : 8; /* block size */
902 cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
903 padding = 4;
904 padding += (cipherblk - (pktout.length + padding) % cipherblk) % cipherblk;
905 pktout.data[4] = padding;
906 for (i = 0; i < padding; i++)
907 pktout.data[pktout.length + i] = random_byte();
908 PUT_32BIT(pktout.data, pktout.length + padding - 4);
909 if (csmac)
910 csmac->generate(pktout.data, pktout.length + padding,
911 outgoing_sequence);
912 outgoing_sequence++; /* whether or not we MACed */
913
914#if 0
915 debug(("Sending packet len=%d\r\n", pktout.length+padding));
916 for (i = 0; i < pktout.length+padding; i++)
917 debug((" %02x", (unsigned char)pktout.data[i]));
918 debug(("\r\n"));
919#endif
920
921 if (cscipher)
922 cscipher->encrypt(pktout.data, pktout.length + padding);
923 maclen = csmac ? csmac->len : 0;
924
925 s_write(pktout.data, pktout.length + padding + maclen);
926}
927
928#if 0
929void bndebug(char *string, Bignum b) {
930 unsigned char *p;
931 int i, len;
932 p = ssh2_mpint_fmt(b, &len);
933 debug(("%s", string));
934 for (i = 0; i < len; i++)
935 debug((" %02x", p[i]));
936 debug(("\r\n"));
937 free(p);
938}
939#endif
940
75cab814 941static void sha_mpint(SHA_State *s, Bignum b) {
7cca0d81 942 unsigned char *p;
943 int len;
944 p = ssh2_mpint_fmt(b, &len);
945 sha_string(s, p, len);
946 free(p);
947}
948
949/*
950 * SSH2 packet decode functions.
951 */
75cab814 952static unsigned long ssh2_pkt_getuint32(void) {
7cca0d81 953 unsigned long value;
954 if (pktin.length - pktin.savedpos < 4)
955 return 0; /* arrgh, no way to decline (FIXME?) */
956 value = GET_32BIT(pktin.data+pktin.savedpos);
957 pktin.savedpos += 4;
958 return value;
959}
75cab814 960static void ssh2_pkt_getstring(char **p, int *length) {
7cca0d81 961 *p = NULL;
962 if (pktin.length - pktin.savedpos < 4)
963 return;
964 *length = GET_32BIT(pktin.data+pktin.savedpos);
965 pktin.savedpos += 4;
966 if (pktin.length - pktin.savedpos < *length)
967 return;
968 *p = pktin.data+pktin.savedpos;
969 pktin.savedpos += *length;
970}
75cab814 971static Bignum ssh2_pkt_getmp(void) {
7cca0d81 972 char *p;
973 int i, j, length;
974 Bignum b;
975
976 ssh2_pkt_getstring(&p, &length);
977 if (!p)
978 return NULL;
8d5de777 979 if (p[0] & 0x80) {
980 bombout(("internal error: Can't handle negative mpints"));
981 return NULL;
982 }
7cca0d81 983 b = newbn((length+1)/2);
984 for (i = 0; i < length; i++) {
985 j = length - 1 - i;
986 if (j & 1)
987 b[j/2+1] |= ((unsigned char)p[i]) << 8;
988 else
989 b[j/2+1] |= ((unsigned char)p[i]);
990 }
991 return b;
992}
993
374330e2 994static int do_ssh_init(void) {
c5e9c988 995 char c, *vsp;
374330e2 996 char version[10];
c5e9c988 997 char vstring[80];
998 char vlog[sizeof(vstring)+20];
374330e2 999 int i;
1000
1001#ifdef FWHACK
1002 i = 0;
1003 while (s_read(&c, 1) == 1) {
1004 if (c == 'S' && i < 2) i++;
1005 else if (c == 'S' && i == 2) i = 2;
1006 else if (c == 'H' && i == 2) break;
1007 else i = 0;
1008 }
1009#else
1010 if (s_read(&c,1) != 1 || c != 'S') return 0;
1011 if (s_read(&c,1) != 1 || c != 'S') return 0;
1012 if (s_read(&c,1) != 1 || c != 'H') return 0;
1013#endif
c5e9c988 1014 strcpy(vstring, "SSH-");
1015 vsp = vstring+4;
374330e2 1016 if (s_read(&c,1) != 1 || c != '-') return 0;
1017 i = 0;
1018 while (1) {
1019 if (s_read(&c,1) != 1)
1020 return 0;
c5e9c988 1021 if (vsp < vstring+sizeof(vstring)-1)
1022 *vsp++ = c;
374330e2 1023 if (i >= 0) {
1024 if (c == '-') {
1025 version[i] = '\0';
1026 i = -1;
1027 } else if (i < sizeof(version)-1)
1028 version[i++] = c;
1029 }
1030 else if (c == '\n')
1031 break;
1032 }
1033
960e736a 1034 rdpkt2_state.incoming_sequence = 0;
1035
c5e9c988 1036 *vsp = 0;
1037 sprintf(vlog, "Server version: %s", vstring);
1038 vlog[strcspn(vlog, "\r\n")] = '\0';
1039 logevent(vlog);
1040
adf799dd 1041 /*
1042 * Server version "1.99" means we can choose whether we use v1
1043 * or v2 protocol. Choice is based on cfg.sshprot.
1044 */
1045 if (ssh_versioncmp(version, cfg.sshprot == 1 ? "2.0" : "1.99") >= 0) {
e5574168 1046 /*
1047 * This is a v2 server. Begin v2 protocol.
1048 */
1049 char *verstring = "SSH-2.0-PuTTY";
1050 SHA_Init(&exhash);
1051 /*
1052 * Hash our version string and their version string.
1053 */
1054 sha_string(&exhash, verstring, strlen(verstring));
1055 sha_string(&exhash, vstring, strcspn(vstring, "\r\n"));
1056 sprintf(vstring, "%s\n", verstring);
1057 sprintf(vlog, "We claim version: %s", verstring);
1058 logevent(vlog);
1059 logevent("Using SSH protocol version 2");
1060 s_write(vstring, strlen(vstring));
1061 ssh_protocol = ssh2_protocol;
6abbf9e3 1062 ssh_version = 2;
e5574168 1063 s_rdpkt = ssh2_rdpkt;
1064 } else {
1065 /*
1066 * This is a v1 server. Begin v1 protocol.
1067 */
1068 sprintf(vstring, "SSH-%s-PuTTY\n",
1069 (ssh_versioncmp(version, "1.5") <= 0 ? version : "1.5"));
1070 sprintf(vlog, "We claim version: %s", vstring);
1071 vlog[strcspn(vlog, "\r\n")] = '\0';
1072 logevent(vlog);
1073 logevent("Using SSH protocol version 1");
1074 s_write(vstring, strlen(vstring));
1075 ssh_protocol = ssh1_protocol;
6abbf9e3 1076 ssh_version = 1;
e5574168 1077 s_rdpkt = ssh1_rdpkt;
1078 }
8ccc75b0 1079 ssh_send_ok = 0;
fef97f43 1080 return 1;
374330e2 1081}
1082
fb09bf1c 1083/*
1084 * Handle the key exchange and user authentication phases.
1085 */
e5574168 1086static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
fb09bf1c 1087{
374330e2 1088 int i, j, len;
374330e2 1089 unsigned char *rsabuf, *keystr1, *keystr2;
1090 unsigned char cookie[8];
1091 struct RSAKey servkey, hostkey;
1092 struct MD5Context md5c;
ccbfb941 1093 static unsigned long supported_ciphers_mask, supported_auths_mask;
7cca0d81 1094 static int tried_publickey;
1095 static unsigned char session_id[16];
bea1ef5f 1096 int cipher_type;
b585ec46 1097 static char username[100];
374330e2 1098
374330e2 1099 crBegin;
1100
fb09bf1c 1101 if (!ispkt) crWaitUntil(ispkt);
374330e2 1102
8d5de777 1103 if (pktin.type != SSH1_SMSG_PUBLIC_KEY) {
1104 bombout(("Public key packet not received"));
1105 crReturn(0);
1106 }
374330e2 1107
c5e9c988 1108 logevent("Received public keys");
374330e2 1109
c5e9c988 1110 memcpy(cookie, pktin.body, 8);
374330e2 1111
7cca0d81 1112 i = makekey(pktin.body+8, &servkey, &keystr1, 0);
1113 j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
374330e2 1114
c5e9c988 1115 /*
1c2a93c4 1116 * Log the host key fingerprint.
c5e9c988 1117 */
c5e9c988 1118 {
1119 char logmsg[80];
1c2a93c4 1120 logevent("Host key fingerprint is:");
c5e9c988 1121 strcpy(logmsg, " ");
1c2a93c4 1122 hostkey.comment = NULL;
1123 rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg),
1124 &hostkey);
c5e9c988 1125 logevent(logmsg);
1126 }
1127
fb09bf1c 1128 supported_ciphers_mask = GET_32BIT(pktin.body+12+i+j);
1129 supported_auths_mask = GET_32BIT(pktin.body+16+i+j);
bea1ef5f 1130
c5e9c988 1131 MD5Init(&md5c);
374330e2 1132 MD5Update(&md5c, keystr2, hostkey.bytes);
1133 MD5Update(&md5c, keystr1, servkey.bytes);
1134 MD5Update(&md5c, pktin.body, 8);
374330e2 1135 MD5Final(session_id, &md5c);
1136
1137 for (i=0; i<32; i++)
1138 session_key[i] = random_byte();
1139
1140 len = (hostkey.bytes > servkey.bytes ? hostkey.bytes : servkey.bytes);
1141
1142 rsabuf = malloc(len);
1143 if (!rsabuf)
1144 fatalbox("Out of memory");
1145
89ee5268 1146 /*
1147 * Verify the host key.
1148 */
1149 {
1150 /*
1151 * First format the key into a string.
1152 */
1153 int len = rsastr_len(&hostkey);
d5859615 1154 char fingerprint[100];
89ee5268 1155 char *keystr = malloc(len);
1156 if (!keystr)
1157 fatalbox("Out of memory");
1158 rsastr_fmt(keystr, &hostkey);
d5859615 1159 rsa_fingerprint(fingerprint, sizeof(fingerprint), &hostkey);
d4857987 1160 verify_ssh_host_key(savedhost, savedport, "rsa", keystr, fingerprint);
89ee5268 1161 free(keystr);
1162 }
374330e2 1163
1164 for (i=0; i<32; i++) {
1165 rsabuf[i] = session_key[i];
1166 if (i < 16)
1167 rsabuf[i] ^= session_id[i];
1168 }
1169
1170 if (hostkey.bytes > servkey.bytes) {
1171 rsaencrypt(rsabuf, 32, &servkey);
1172 rsaencrypt(rsabuf, servkey.bytes, &hostkey);
1173 } else {
1174 rsaencrypt(rsabuf, 32, &hostkey);
1175 rsaencrypt(rsabuf, hostkey.bytes, &servkey);
1176 }
1177
c5e9c988 1178 logevent("Encrypted session key");
1179
bea1ef5f 1180 cipher_type = cfg.cipher == CIPHER_BLOWFISH ? SSH_CIPHER_BLOWFISH :
9697bfd2 1181 cfg.cipher == CIPHER_DES ? SSH_CIPHER_DES :
bea1ef5f 1182 SSH_CIPHER_3DES;
1183 if ((supported_ciphers_mask & (1 << cipher_type)) == 0) {
1184 c_write("Selected cipher not supported, falling back to 3DES\r\n", 53);
1185 cipher_type = SSH_CIPHER_3DES;
1186 }
c5e9c988 1187 switch (cipher_type) {
1188 case SSH_CIPHER_3DES: logevent("Using 3DES encryption"); break;
1189 case SSH_CIPHER_DES: logevent("Using single-DES encryption"); break;
1190 case SSH_CIPHER_BLOWFISH: logevent("Using Blowfish encryption"); break;
1191 }
bea1ef5f 1192
e5574168 1193 send_packet(SSH1_CMSG_SESSION_KEY,
fb09bf1c 1194 PKT_CHAR, cipher_type,
1195 PKT_DATA, cookie, 8,
1196 PKT_CHAR, (len*8) >> 8, PKT_CHAR, (len*8) & 0xFF,
1197 PKT_DATA, rsabuf, len,
1198 PKT_INT, 0,
1199 PKT_END);
1200
c5e9c988 1201 logevent("Trying to enable encryption...");
374330e2 1202
1203 free(rsabuf);
1204
5e8358ad 1205 cipher = cipher_type == SSH_CIPHER_BLOWFISH ? &ssh_blowfish_ssh1 :
9697bfd2 1206 cipher_type == SSH_CIPHER_DES ? &ssh_des :
bea1ef5f 1207 &ssh_3des;
374330e2 1208 cipher->sesskey(session_key);
1209
fb09bf1c 1210 crWaitUntil(ispkt);
374330e2 1211
8d5de777 1212 if (pktin.type != SSH1_SMSG_SUCCESS) {
1213 bombout(("Encryption not successfully enabled"));
1214 crReturn(0);
1215 }
374330e2 1216
c5e9c988 1217 logevent("Successfully started encryption");
1218
374330e2 1219 fflush(stdout);
1220 {
374330e2 1221 static int pos = 0;
1222 static char c;
67779be7 1223 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
374330e2 1224 c_write("login as: ", 10);
67779be7 1225 ssh_send_ok = 1;
374330e2 1226 while (pos >= 0) {
fb09bf1c 1227 crWaitUntil(!ispkt);
374330e2 1228 while (inlen--) switch (c = *in++) {
1229 case 10: case 13:
1230 username[pos] = 0;
1231 pos = -1;
1232 break;
1233 case 8: case 127:
1234 if (pos > 0) {
1235 c_write("\b \b", 3);
1236 pos--;
1237 }
1238 break;
1239 case 21: case 27:
1240 while (pos > 0) {
1241 c_write("\b \b", 3);
1242 pos--;
1243 }
1244 break;
1245 case 3: case 4:
1246 random_save_seed();
1247 exit(0);
1248 break;
1249 default:
40d24aa6 1250 if (((c >= ' ' && c <= '~') ||
1251 ((unsigned char)c >= 160)) && pos < 40) {
374330e2 1252 username[pos++] = c;
1253 c_write(&c, 1);
1254 }
1255 break;
1256 }
1257 }
1258 c_write("\r\n", 2);
1259 username[strcspn(username, "\n\r")] = '\0';
1260 } else {
1261 char stuff[200];
1262 strncpy(username, cfg.username, 99);
1263 username[99] = '\0';
67779be7 1264 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
fb09bf1c 1265 sprintf(stuff, "Sent username \"%s\".\r\n", username);
4017be6d 1266 c_write(stuff, strlen(stuff));
fb09bf1c 1267 }
374330e2 1268 }
fb09bf1c 1269
e5574168 1270 send_packet(SSH1_CMSG_USER, PKT_STR, username, PKT_END);
c5e9c988 1271 {
1272 char userlog[20+sizeof(username)];
1273 sprintf(userlog, "Sent username \"%s\"", username);
1274 logevent(userlog);
1275 }
374330e2 1276 }
1277
fb09bf1c 1278 crWaitUntil(ispkt);
374330e2 1279
7cca0d81 1280 tried_publickey = 0;
1281
e5574168 1282 while (pktin.type == SSH1_SMSG_FAILURE) {
374330e2 1283 static char password[100];
a52f067e 1284 static char prompt[200];
374330e2 1285 static int pos;
1286 static char c;
ccbfb941 1287 static int pwpkt_type;
ccbfb941 1288 /*
1289 * Show password prompt, having first obtained it via a TIS
18515c51 1290 * or CryptoCard exchange if we're doing TIS or CryptoCard
1291 * authentication.
ccbfb941 1292 */
e5574168 1293 pwpkt_type = SSH1_CMSG_AUTH_PASSWORD;
5c58ad2d 1294 if (agent_exists()) {
1295 /*
1296 * Attempt RSA authentication using Pageant.
1297 */
1298 static unsigned char request[5], *response, *p;
1299 static int responselen;
1300 static int i, nkeys;
1301 static int authed = FALSE;
1302 void *r;
1303
1304 logevent("Pageant is running. Requesting keys.");
1305
1306 /* Request the keys held by the agent. */
1307 PUT_32BIT(request, 1);
1308 request[4] = SSH_AGENTC_REQUEST_RSA_IDENTITIES;
1309 agent_query(request, 5, &r, &responselen);
1310 response = (unsigned char *)r;
1311 if (response) {
1312 p = response + 5;
1313 nkeys = GET_32BIT(p); p += 4;
1314 { char buf[64]; sprintf(buf, "Pageant has %d keys", nkeys);
1315 logevent(buf); }
1316 for (i = 0; i < nkeys; i++) {
1317 static struct RSAKey key;
1318 static Bignum challenge;
b8bb811a 1319 static char *commentp;
1320 static int commentlen;
5c58ad2d 1321
1322 { char buf[64]; sprintf(buf, "Trying Pageant key #%d", i);
1323 logevent(buf); }
1324 p += 4;
1325 p += ssh1_read_bignum(p, &key.exponent);
1326 p += ssh1_read_bignum(p, &key.modulus);
b8bb811a 1327 commentlen = GET_32BIT(p); p += 4;
1328 commentp = p; p += commentlen;
5c58ad2d 1329 send_packet(SSH1_CMSG_AUTH_RSA,
1330 PKT_BIGNUM, key.modulus, PKT_END);
1331 crWaitUntil(ispkt);
1332 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1333 logevent("Key refused");
1334 continue;
1335 }
1336 logevent("Received RSA challenge");
1337 ssh1_read_bignum(pktin.body, &challenge);
1338 {
1339 char *agentreq, *q, *ret;
1340 int len, retlen;
1341 len = 1 + 4; /* message type, bit count */
1342 len += ssh1_bignum_length(key.exponent);
1343 len += ssh1_bignum_length(key.modulus);
1344 len += ssh1_bignum_length(challenge);
1345 len += 16; /* session id */
1346 len += 4; /* response format */
1347 agentreq = malloc(4 + len);
1348 PUT_32BIT(agentreq, len);
1349 q = agentreq + 4;
1350 *q++ = SSH_AGENTC_RSA_CHALLENGE;
1351 PUT_32BIT(q, ssh1_bignum_bitcount(key.modulus));
1352 q += 4;
1353 q += ssh1_write_bignum(q, key.exponent);
1354 q += ssh1_write_bignum(q, key.modulus);
1355 q += ssh1_write_bignum(q, challenge);
1356 memcpy(q, session_id, 16); q += 16;
1357 PUT_32BIT(q, 1); /* response format */
1358 agent_query(agentreq, len+4, &ret, &retlen);
1359 free(agentreq);
1360 if (ret) {
1361 if (ret[4] == SSH_AGENT_RSA_RESPONSE) {
1362 logevent("Sending Pageant's response");
1363 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1364 PKT_DATA, ret+5, 16, PKT_END);
1365 free(ret);
1366 crWaitUntil(ispkt);
1367 if (pktin.type == SSH1_SMSG_SUCCESS) {
1368 logevent("Pageant's response accepted");
c4fa2fce 1369 if (flags & FLAG_VERBOSE) {
1370 c_write("Authenticated using RSA key \"",
1371 29);
1372 c_write(commentp, commentlen);
1373 c_write("\" from agent\r\n", 14);
1374 }
5c58ad2d 1375 authed = TRUE;
1376 } else
1377 logevent("Pageant's response not accepted");
1378 } else {
1379 logevent("Pageant failed to answer challenge");
1380 free(ret);
1381 }
1382 } else {
1383 logevent("No reply received from Pageant");
1384 }
1385 }
1386 freebn(key.exponent);
1387 freebn(key.modulus);
1388 freebn(challenge);
1389 if (authed)
1390 break;
1391 }
1392 }
1393 if (authed)
1394 break;
1395 }
7cca0d81 1396 if (*cfg.keyfile && !tried_publickey)
1397 pwpkt_type = SSH1_CMSG_AUTH_RSA;
fb09bf1c 1398
a52f067e 1399 if (pktin.type == SSH1_SMSG_FAILURE &&
1400 cfg.try_tis_auth &&
1401 (supported_auths_mask & (1<<SSH1_AUTH_TIS))) {
1402 pwpkt_type = SSH1_CMSG_AUTH_TIS_RESPONSE;
1403 logevent("Requested TIS authentication");
1404 send_packet(SSH1_CMSG_AUTH_TIS, PKT_END);
1405 crWaitUntil(ispkt);
1406 if (pktin.type != SSH1_SMSG_AUTH_TIS_CHALLENGE) {
1407 logevent("TIS authentication declined");
1408 if (flags & FLAG_INTERACTIVE)
1409 c_write("TIS authentication refused.\r\n", 29);
1410 } else {
1411 int challengelen = ((pktin.body[0] << 24) |
1412 (pktin.body[1] << 16) |
1413 (pktin.body[2] << 8) |
1414 (pktin.body[3]));
1415 logevent("Received TIS challenge");
1416 if (challengelen > sizeof(prompt)-1)
1417 challengelen = sizeof(prompt)-1; /* prevent overrun */
1418 memcpy(prompt, pktin.body+4, challengelen);
1419 prompt[challengelen] = '\0';
1420 }
1421 }
1422 if (pktin.type == SSH1_SMSG_FAILURE &&
1423 cfg.try_tis_auth &&
1424 (supported_auths_mask & (1<<SSH1_AUTH_CCARD))) {
1425 pwpkt_type = SSH1_CMSG_AUTH_CCARD_RESPONSE;
1426 logevent("Requested CryptoCard authentication");
1427 send_packet(SSH1_CMSG_AUTH_CCARD, PKT_END);
1428 crWaitUntil(ispkt);
1429 if (pktin.type != SSH1_SMSG_AUTH_CCARD_CHALLENGE) {
1430 logevent("CryptoCard authentication declined");
1431 c_write("CryptoCard authentication refused.\r\n", 29);
1432 } else {
1433 int challengelen = ((pktin.body[0] << 24) |
1434 (pktin.body[1] << 16) |
1435 (pktin.body[2] << 8) |
1436 (pktin.body[3]));
1437 logevent("Received CryptoCard challenge");
1438 if (challengelen > sizeof(prompt)-1)
1439 challengelen = sizeof(prompt)-1; /* prevent overrun */
1440 memcpy(prompt, pktin.body+4, challengelen);
1441 strncpy(prompt + challengelen, "\r\nResponse : ",
1442 sizeof(prompt)-challengelen);
1443 prompt[sizeof(prompt)-1] = '\0';
1444 }
1445 }
1446 if (pwpkt_type == SSH1_CMSG_AUTH_PASSWORD) {
1447 sprintf(prompt, "%.90s@%.90s's password: ",
b585ec46 1448 username, savedhost);
a52f067e 1449 }
1450 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1451 char *comment = NULL;
1452 if (flags & FLAG_VERBOSE)
1453 c_write("Trying public key authentication.\r\n", 35);
1454 if (!rsakey_encrypted(cfg.keyfile, &comment)) {
1455 if (flags & FLAG_VERBOSE)
1456 c_write("No passphrase required.\r\n", 25);
1457 goto tryauth;
1458 }
1459 sprintf(prompt, "Passphrase for key \"%.100s\": ", comment);
1460 free(comment);
1461 }
1462
d8426c54 1463 if (ssh_get_password) {
85ee8208 1464 if (!ssh_get_password(prompt, password, sizeof(password))) {
1465 /*
1466 * get_password failed to get a password (for
1467 * example because one was supplied on the command
1468 * line which has already failed to work).
1469 * Terminate.
1470 */
1471 logevent("No more passwords to try");
1472 ssh_state = SSH_STATE_CLOSED;
1473 crReturn(1);
1474 }
fb09bf1c 1475 } else {
a52f067e 1476 c_write(prompt, strlen(prompt));
7cca0d81 1477 pos = 0;
67779be7 1478 ssh_send_ok = 1;
7cca0d81 1479 while (pos >= 0) {
1480 crWaitUntil(!ispkt);
1481 while (inlen--) switch (c = *in++) {
1482 case 10: case 13:
1483 password[pos] = 0;
1484 pos = -1;
1485 break;
1486 case 8: case 127:
1487 if (pos > 0)
1488 pos--;
1489 break;
1490 case 21: case 27:
1491 pos = 0;
1492 break;
1493 case 3: case 4:
1494 random_save_seed();
1495 exit(0);
1496 break;
1497 default:
1498 if (((c >= ' ' && c <= '~') ||
1499 ((unsigned char)c >= 160)) && pos < sizeof(password))
1500 password[pos++] = c;
1501 break;
1502 }
1503 }
1504 c_write("\r\n", 2);
a52f067e 1505 }
fb09bf1c 1506
7cca0d81 1507 tryauth:
1508 if (pwpkt_type == SSH1_CMSG_AUTH_RSA) {
1509 /*
1510 * Try public key authentication with the specified
1511 * key file.
1512 */
1513 static struct RSAKey pubkey;
1514 static Bignum challenge, response;
1515 static int i;
1516 static unsigned char buffer[32];
1517
1518 tried_publickey = 1;
1519 i = loadrsakey(cfg.keyfile, &pubkey, password);
1520 if (i == 0) {
1521 c_write("Couldn't load public key from ", 30);
1522 c_write(cfg.keyfile, strlen(cfg.keyfile));
1523 c_write(".\r\n", 3);
1524 continue; /* go and try password */
1525 }
1526 if (i == -1) {
1527 c_write("Wrong passphrase.\r\n", 19);
1528 tried_publickey = 0;
1529 continue; /* try again */
1530 }
1531
1532 /*
1533 * Send a public key attempt.
1534 */
1535 send_packet(SSH1_CMSG_AUTH_RSA,
1536 PKT_BIGNUM, pubkey.modulus, PKT_END);
1537
1538 crWaitUntil(ispkt);
1539 if (pktin.type == SSH1_SMSG_FAILURE) {
a52f067e 1540 c_write("Server refused our public key.\r\n", 32);
7cca0d81 1541 continue; /* go and try password */
1542 }
8d5de777 1543 if (pktin.type != SSH1_SMSG_AUTH_RSA_CHALLENGE) {
1544 bombout(("Bizarre response to offer of public key"));
1545 crReturn(0);
1546 }
7cca0d81 1547 ssh1_read_bignum(pktin.body, &challenge);
1548 response = rsadecrypt(challenge, &pubkey);
1549 freebn(pubkey.private_exponent); /* burn the evidence */
1550
1551 for (i = 0; i < 32; i += 2) {
1552 buffer[i] = response[16-i/2] >> 8;
1553 buffer[i+1] = response[16-i/2] & 0xFF;
1554 }
1555
1556 MD5Init(&md5c);
1557 MD5Update(&md5c, buffer, 32);
1558 MD5Update(&md5c, session_id, 16);
1559 MD5Final(buffer, &md5c);
1560
1561 send_packet(SSH1_CMSG_AUTH_RSA_RESPONSE,
1562 PKT_DATA, buffer, 16, PKT_END);
1563
1564 crWaitUntil(ispkt);
1565 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1566 if (flags & FLAG_VERBOSE)
1567 c_write("Failed to authenticate with our public key.\r\n",
1568 45);
7cca0d81 1569 continue; /* go and try password */
1570 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1571 bombout(("Bizarre response to RSA authentication response"));
1572 crReturn(0);
7cca0d81 1573 }
1574
1575 break; /* we're through! */
1576 } else {
1577 send_packet(pwpkt_type, PKT_STR, password, PKT_END);
1578 }
c5e9c988 1579 logevent("Sent password");
374330e2 1580 memset(password, 0, strlen(password));
fb09bf1c 1581 crWaitUntil(ispkt);
e5574168 1582 if (pktin.type == SSH1_SMSG_FAILURE) {
4017be6d 1583 if (flags & FLAG_VERBOSE)
1584 c_write("Access denied\r\n", 15);
c5e9c988 1585 logevent("Authentication refused");
e5574168 1586 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
fb09bf1c 1587 logevent("Received disconnect request");
85ee8208 1588 ssh_state = SSH_STATE_CLOSED;
1589 crReturn(1);
e5574168 1590 } else if (pktin.type != SSH1_SMSG_SUCCESS) {
8d5de777 1591 bombout(("Strange packet received, type %d", pktin.type));
1592 crReturn(0);
374330e2 1593 }
1594 }
1595
c5e9c988 1596 logevent("Authentication successful");
1597
fb09bf1c 1598 crFinish(1);
1599}
1600
e5574168 1601static void ssh1_protocol(unsigned char *in, int inlen, int ispkt) {
fb09bf1c 1602 crBegin;
1603
1604 random_init();
1605
e5574168 1606 while (!do_ssh1_login(in, inlen, ispkt)) {
fb09bf1c 1607 crReturnV;
85ee8208 1608 }
1609 if (ssh_state == SSH_STATE_CLOSED)
1610 crReturnV;
fb09bf1c 1611
979310f1 1612 if (cfg.agentfwd && agent_exists()) {
dacbd0e8 1613 logevent("Requesting agent forwarding");
1614 send_packet(SSH1_CMSG_AGENT_REQUEST_FORWARDING, PKT_END);
1615 do { crReturnV; } while (!ispkt);
1616 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 1617 bombout(("Protocol confusion"));
1618 crReturnV;
dacbd0e8 1619 } else if (pktin.type == SSH1_SMSG_FAILURE) {
1620 logevent("Agent forwarding refused");
1621 } else
1622 logevent("Agent forwarding enabled");
1623 }
1624
fef97f43 1625 if (!cfg.nopty) {
e5574168 1626 send_packet(SSH1_CMSG_REQUEST_PTY,
fb09bf1c 1627 PKT_STR, cfg.termtype,
1628 PKT_INT, rows, PKT_INT, cols,
1629 PKT_INT, 0, PKT_INT, 0,
1630 PKT_CHAR, 0,
1631 PKT_END);
fef97f43 1632 ssh_state = SSH_STATE_INTERMED;
1633 do { crReturnV; } while (!ispkt);
e5574168 1634 if (pktin.type != SSH1_SMSG_SUCCESS && pktin.type != SSH1_SMSG_FAILURE) {
8d5de777 1635 bombout(("Protocol confusion"));
1636 crReturnV;
e5574168 1637 } else if (pktin.type == SSH1_SMSG_FAILURE) {
fef97f43 1638 c_write("Server refused to allocate pty\r\n", 32);
1639 }
c5e9c988 1640 logevent("Allocated pty");
374330e2 1641 }
1642
6abbf9e3 1643 if (*cfg.remote_cmd)
1644 send_packet(SSH1_CMSG_EXEC_CMD, PKT_STR, cfg.remote_cmd, PKT_END);
1645 else
1646 send_packet(SSH1_CMSG_EXEC_SHELL, PKT_END);
c5e9c988 1647 logevent("Started session");
374330e2 1648
1649 ssh_state = SSH_STATE_SESSION;
1650 if (size_needed)
1651 ssh_size();
1652
8ccc75b0 1653 ssh_send_ok = 1;
dacbd0e8 1654 ssh_channels = newtree234(ssh_channelcmp);
6f34e365 1655 begin_session();
374330e2 1656 while (1) {
1657 crReturnV;
1658 if (ispkt) {
e5574168 1659 if (pktin.type == SSH1_SMSG_STDOUT_DATA ||
1660 pktin.type == SSH1_SMSG_STDERR_DATA) {
fb09bf1c 1661 long len = GET_32BIT(pktin.body);
3bdaf79d 1662 c_writedata(pktin.body+4, len);
e5574168 1663 } else if (pktin.type == SSH1_MSG_DISCONNECT) {
21248260 1664 ssh_state = SSH_STATE_CLOSED;
c5e9c988 1665 logevent("Received disconnect request");
dacbd0e8 1666 } else if (pktin.type == SSH1_SMSG_AGENT_OPEN) {
1667 /* Remote side is trying to open a channel to talk to our
1668 * agent. Give them back a local channel number. */
d211621f 1669 unsigned i = 1;
dacbd0e8 1670 struct ssh_channel *c;
1671 enum234 e;
1672 for (c = first234(ssh_channels, &e); c; c = next234(&e)) {
1673 if (c->localid > i)
1674 break; /* found a free number */
1675 i = c->localid + 1;
1676 }
1677 c = malloc(sizeof(struct ssh_channel));
1678 c->remoteid = GET_32BIT(pktin.body);
1679 c->localid = i;
b8bb811a 1680 c->closes = 0;
dacbd0e8 1681 c->type = SSH1_SMSG_AGENT_OPEN; /* identify channel type */
bb487ce2 1682 c->u.a.lensofar = 0;
dacbd0e8 1683 add234(ssh_channels, c);
1684 send_packet(SSH1_MSG_CHANNEL_OPEN_CONFIRMATION,
1685 PKT_INT, c->remoteid, PKT_INT, c->localid,
1686 PKT_END);
1687 } else if (pktin.type == SSH1_MSG_CHANNEL_CLOSE ||
1688 pktin.type == SSH1_MSG_CHANNEL_CLOSE_CONFIRMATION) {
1689 /* Remote side closes a channel. */
d211621f 1690 unsigned i = GET_32BIT(pktin.body);
dacbd0e8 1691 struct ssh_channel *c;
1692 c = find234(ssh_channels, &i, ssh_channelfind);
1693 if (c) {
1694 int closetype;
1695 closetype = (pktin.type == SSH1_MSG_CHANNEL_CLOSE ? 1 : 2);
1696 send_packet(pktin.type, PKT_INT, c->remoteid, PKT_END);
1697 c->closes |= closetype;
1698 if (c->closes == 3) {
1699 del234(ssh_channels, c);
1700 free(c);
1701 }
1702 }
1703 } else if (pktin.type == SSH1_MSG_CHANNEL_DATA) {
1704 /* Data sent down one of our channels. */
1705 int i = GET_32BIT(pktin.body);
1706 int len = GET_32BIT(pktin.body+4);
1707 unsigned char *p = pktin.body+8;
1708 struct ssh_channel *c;
1709 c = find234(ssh_channels, &i, ssh_channelfind);
1710 if (c) {
1711 switch(c->type) {
1712 case SSH1_SMSG_AGENT_OPEN:
1713 /* Data for an agent message. Buffer it. */
1714 while (len > 0) {
1715 if (c->u.a.lensofar < 4) {
1716 int l = min(4 - c->u.a.lensofar, len);
1717 memcpy(c->u.a.msglen + c->u.a.lensofar, p, l);
1718 p += l; len -= l; c->u.a.lensofar += l;
1719 }
1720 if (c->u.a.lensofar == 4) {
1721 c->u.a.totallen = 4 + GET_32BIT(c->u.a.msglen);
1722 c->u.a.message = malloc(c->u.a.totallen);
1723 memcpy(c->u.a.message, c->u.a.msglen, 4);
1724 }
1725 if (c->u.a.lensofar >= 4 && len > 0) {
1726 int l = min(c->u.a.totallen - c->u.a.lensofar, len);
1727 memcpy(c->u.a.message + c->u.a.lensofar, p, l);
1728 p += l; len -= l; c->u.a.lensofar += l;
1729 }
1730 if (c->u.a.lensofar == c->u.a.totallen) {
1731 void *reply, *sentreply;
1732 int replylen;
1733 agent_query(c->u.a.message, c->u.a.totallen,
1734 &reply, &replylen);
1735 if (reply)
1736 sentreply = reply;
1737 else {
1738 /* Fake SSH_AGENT_FAILURE. */
1739 sentreply = "\0\0\0\1\5";
1740 replylen = 5;
1741 }
1742 send_packet(SSH1_MSG_CHANNEL_DATA,
1743 PKT_INT, c->remoteid,
1744 PKT_INT, replylen,
1745 PKT_DATA, sentreply, replylen,
1746 PKT_END);
1747 if (reply)
1748 free(reply);
1749 free(c->u.a.message);
1750 c->u.a.lensofar = 0;
1751 }
1752 }
1753 break;
1754 }
1755 }
e5574168 1756 } else if (pktin.type == SSH1_SMSG_SUCCESS) {
972a41c8 1757 /* may be from EXEC_SHELL on some servers */
e5574168 1758 } else if (pktin.type == SSH1_SMSG_FAILURE) {
972a41c8 1759 /* may be from EXEC_SHELL on some servers
374330e2 1760 * if no pty is available or in other odd cases. Ignore */
e5574168 1761 } else if (pktin.type == SSH1_SMSG_EXIT_STATUS) {
1762 send_packet(SSH1_CMSG_EXIT_CONFIRMATION, PKT_END);
374330e2 1763 } else {
8d5de777 1764 bombout(("Strange packet received: type %d", pktin.type));
1765 crReturnV;
374330e2 1766 }
1767 } else {
e5574168 1768 send_packet(SSH1_CMSG_STDIN_DATA,
fb09bf1c 1769 PKT_INT, inlen, PKT_DATA, in, inlen, PKT_END);
374330e2 1770 }
1771 }
1772
1773 crFinishV;
1774}
1775
1776/*
e5574168 1777 * Utility routine for decoding comma-separated strings in KEXINIT.
1778 */
75cab814 1779static int in_commasep_string(char *needle, char *haystack, int haylen) {
e5574168 1780 int needlen = strlen(needle);
1781 while (1) {
1782 /*
1783 * Is it at the start of the string?
1784 */
1785 if (haylen >= needlen && /* haystack is long enough */
1786 !memcmp(needle, haystack, needlen) && /* initial match */
1787 (haylen == needlen || haystack[needlen] == ',')
1788 /* either , or EOS follows */
1789 )
1790 return 1;
1791 /*
1792 * If not, search for the next comma and resume after that.
1793 * If no comma found, terminate.
1794 */
1795 while (haylen > 0 && *haystack != ',')
1796 haylen--, haystack++;
1797 if (haylen == 0)
1798 return 0;
1799 haylen--, haystack++; /* skip over comma itself */
1800 }
1801}
1802
1803/*
d39f364a 1804 * SSH2 key creation method.
1805 */
75cab814 1806static void ssh2_mkkey(Bignum K, char *H, char chr, char *keyspace) {
d39f364a 1807 SHA_State s;
1808 /* First 20 bytes. */
1809 SHA_Init(&s);
1810 sha_mpint(&s, K);
1811 SHA_Bytes(&s, H, 20);
1812 SHA_Bytes(&s, &chr, 1);
1813 SHA_Bytes(&s, H, 20);
1814 SHA_Final(&s, keyspace);
1815 /* Next 20 bytes. */
1816 SHA_Init(&s);
1817 sha_mpint(&s, K);
1818 SHA_Bytes(&s, H, 20);
1819 SHA_Bytes(&s, keyspace, 20);
1820 SHA_Final(&s, keyspace+20);
1821}
1822
1823/*
7cca0d81 1824 * Handle the SSH2 transport layer.
e5574168 1825 */
7cca0d81 1826static int do_ssh2_transport(unsigned char *in, int inlen, int ispkt)
e5574168 1827{
1828 static int i, len;
1829 static char *str;
1830 static Bignum e, f, K;
57476f6b 1831 static const struct ssh_cipher *cscipher_tobe = NULL;
1832 static const struct ssh_cipher *sccipher_tobe = NULL;
1833 static const struct ssh_mac *csmac_tobe = NULL;
1834 static const struct ssh_mac *scmac_tobe = NULL;
1835 static const struct ssh_compress *cscomp_tobe = NULL;
1836 static const struct ssh_compress *sccomp_tobe = NULL;
d5859615 1837 static char *hostkeydata, *sigdata, *keystr, *fingerprint;
e5574168 1838 static int hostkeylen, siglen;
1839 static unsigned char exchange_hash[20];
d39f364a 1840 static unsigned char keyspace[40];
57476f6b 1841 static const struct ssh_cipher *preferred_cipher;
e5574168 1842
1843 crBegin;
7cca0d81 1844 random_init();
e5574168 1845
5e8358ad 1846 /*
1847 * Set up the preferred cipher.
1848 */
1849 if (cfg.cipher == CIPHER_BLOWFISH) {
57476f6b 1850 preferred_cipher = &ssh_blowfish_ssh2;
5e8358ad 1851 } else if (cfg.cipher == CIPHER_DES) {
1852 logevent("Single DES not supported in SSH2; using 3DES");
57476f6b 1853 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 1854 } else if (cfg.cipher == CIPHER_3DES) {
57476f6b 1855 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 1856 } else {
1857 /* Shouldn't happen, but we do want to initialise to _something_. */
57476f6b 1858 preferred_cipher = &ssh_3des_ssh2;
5e8358ad 1859 }
1860
7cca0d81 1861 begin_key_exchange:
e5574168 1862 /*
1863 * Construct and send our key exchange packet.
1864 */
1865 ssh2_pkt_init(SSH2_MSG_KEXINIT);
1866 for (i = 0; i < 16; i++)
1867 ssh2_pkt_addbyte((unsigned char)random_byte());
1868 /* List key exchange algorithms. */
1869 ssh2_pkt_addstring_start();
1870 for (i = 0; i < lenof(kex_algs); i++) {
1871 ssh2_pkt_addstring_str(kex_algs[i]->name);
1872 if (i < lenof(kex_algs)-1)
1873 ssh2_pkt_addstring_str(",");
1874 }
1875 /* List server host key algorithms. */
1876 ssh2_pkt_addstring_start();
1877 for (i = 0; i < lenof(hostkey_algs); i++) {
1878 ssh2_pkt_addstring_str(hostkey_algs[i]->name);
1879 if (i < lenof(hostkey_algs)-1)
1880 ssh2_pkt_addstring_str(",");
1881 }
1882 /* List client->server encryption algorithms. */
1883 ssh2_pkt_addstring_start();
729e54b4 1884 for (i = 0; i < lenof(ciphers)+1; i++) {
1885 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 1886 ssh2_pkt_addstring_str(c->name);
729e54b4 1887 if (i < lenof(ciphers))
e5574168 1888 ssh2_pkt_addstring_str(",");
1889 }
1890 /* List server->client encryption algorithms. */
1891 ssh2_pkt_addstring_start();
729e54b4 1892 for (i = 0; i < lenof(ciphers)+1; i++) {
1893 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 1894 ssh2_pkt_addstring_str(c->name);
729e54b4 1895 if (i < lenof(ciphers))
e5574168 1896 ssh2_pkt_addstring_str(",");
1897 }
1898 /* List client->server MAC algorithms. */
1899 ssh2_pkt_addstring_start();
1900 for (i = 0; i < lenof(macs); i++) {
1901 ssh2_pkt_addstring_str(macs[i]->name);
1902 if (i < lenof(macs)-1)
1903 ssh2_pkt_addstring_str(",");
1904 }
1905 /* List server->client MAC algorithms. */
1906 ssh2_pkt_addstring_start();
1907 for (i = 0; i < lenof(macs); i++) {
1908 ssh2_pkt_addstring_str(macs[i]->name);
1909 if (i < lenof(macs)-1)
1910 ssh2_pkt_addstring_str(",");
1911 }
1912 /* List client->server compression algorithms. */
1913 ssh2_pkt_addstring_start();
1914 for (i = 0; i < lenof(compressions); i++) {
1915 ssh2_pkt_addstring_str(compressions[i]->name);
1916 if (i < lenof(compressions)-1)
1917 ssh2_pkt_addstring_str(",");
1918 }
1919 /* List server->client compression algorithms. */
1920 ssh2_pkt_addstring_start();
1921 for (i = 0; i < lenof(compressions); i++) {
1922 ssh2_pkt_addstring_str(compressions[i]->name);
1923 if (i < lenof(compressions)-1)
1924 ssh2_pkt_addstring_str(",");
1925 }
1926 /* List client->server languages. Empty list. */
1927 ssh2_pkt_addstring_start();
1928 /* List server->client languages. Empty list. */
1929 ssh2_pkt_addstring_start();
1930 /* First KEX packet does _not_ follow, because we're not that brave. */
1931 ssh2_pkt_addbool(FALSE);
1932 /* Reserved. */
1933 ssh2_pkt_adduint32(0);
1934 sha_string(&exhash, pktout.data+5, pktout.length-5);
1935 ssh2_pkt_send();
1936
1937 if (!ispkt) crWaitUntil(ispkt);
1938 sha_string(&exhash, pktin.data+5, pktin.length-5);
1939
1940 /*
1941 * Now examine the other side's KEXINIT to see what we're up
1942 * to.
1943 */
7cca0d81 1944 if (pktin.type != SSH2_MSG_KEXINIT) {
8d5de777 1945 bombout(("expected key exchange packet from server"));
1946 crReturn(0);
7cca0d81 1947 }
e5574168 1948 kex = NULL; hostkey = NULL; cscipher_tobe = NULL; sccipher_tobe = NULL;
1949 csmac_tobe = NULL; scmac_tobe = NULL; cscomp_tobe = NULL; sccomp_tobe = NULL;
1950 pktin.savedpos += 16; /* skip garbage cookie */
1951 ssh2_pkt_getstring(&str, &len); /* key exchange algorithms */
1952 for (i = 0; i < lenof(kex_algs); i++) {
1953 if (in_commasep_string(kex_algs[i]->name, str, len)) {
1954 kex = kex_algs[i];
1955 break;
1956 }
1957 }
1958 ssh2_pkt_getstring(&str, &len); /* host key algorithms */
1959 for (i = 0; i < lenof(hostkey_algs); i++) {
1960 if (in_commasep_string(hostkey_algs[i]->name, str, len)) {
1961 hostkey = hostkey_algs[i];
1962 break;
1963 }
1964 }
1965 ssh2_pkt_getstring(&str, &len); /* client->server cipher */
729e54b4 1966 for (i = 0; i < lenof(ciphers)+1; i++) {
1967 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 1968 if (in_commasep_string(c->name, str, len)) {
729e54b4 1969 cscipher_tobe = c;
e5574168 1970 break;
1971 }
1972 }
1973 ssh2_pkt_getstring(&str, &len); /* server->client cipher */
729e54b4 1974 for (i = 0; i < lenof(ciphers)+1; i++) {
1975 const struct ssh_cipher *c = i==0 ? preferred_cipher : ciphers[i-1];
57476f6b 1976 if (in_commasep_string(c->name, str, len)) {
729e54b4 1977 sccipher_tobe = c;
e5574168 1978 break;
1979 }
1980 }
1981 ssh2_pkt_getstring(&str, &len); /* client->server mac */
1982 for (i = 0; i < lenof(macs); i++) {
1983 if (in_commasep_string(macs[i]->name, str, len)) {
1984 csmac_tobe = macs[i];
1985 break;
1986 }
1987 }
1988 ssh2_pkt_getstring(&str, &len); /* server->client mac */
1989 for (i = 0; i < lenof(macs); i++) {
1990 if (in_commasep_string(macs[i]->name, str, len)) {
1991 scmac_tobe = macs[i];
1992 break;
1993 }
1994 }
1995 ssh2_pkt_getstring(&str, &len); /* client->server compression */
1996 for (i = 0; i < lenof(compressions); i++) {
1997 if (in_commasep_string(compressions[i]->name, str, len)) {
1998 cscomp_tobe = compressions[i];
1999 break;
2000 }
2001 }
2002 ssh2_pkt_getstring(&str, &len); /* server->client compression */
2003 for (i = 0; i < lenof(compressions); i++) {
2004 if (in_commasep_string(compressions[i]->name, str, len)) {
2005 sccomp_tobe = compressions[i];
2006 break;
2007 }
2008 }
e5574168 2009
2010 /*
2011 * Currently we only support Diffie-Hellman and DSS, so let's
2012 * bomb out if those aren't selected.
2013 */
8d5de777 2014 if (kex != &ssh_diffiehellman || hostkey != &ssh_dss) {
2015 bombout(("internal fault: chaos in SSH 2 transport layer"));
2016 crReturn(0);
2017 }
e5574168 2018
2019 /*
2020 * Now we begin the fun. Generate and send e for Diffie-Hellman.
2021 */
2022 e = dh_create_e();
e5574168 2023 ssh2_pkt_init(SSH2_MSG_KEXDH_INIT);
2024 ssh2_pkt_addmp(e);
2025 ssh2_pkt_send();
2026
2027 crWaitUntil(ispkt);
7cca0d81 2028 if (pktin.type != SSH2_MSG_KEXDH_REPLY) {
8d5de777 2029 bombout(("expected key exchange packet from server"));
2030 crReturn(0);
7cca0d81 2031 }
e5574168 2032 ssh2_pkt_getstring(&hostkeydata, &hostkeylen);
2033 f = ssh2_pkt_getmp();
e5574168 2034 ssh2_pkt_getstring(&sigdata, &siglen);
2035
2036 K = dh_find_K(f);
e5574168 2037
2038 sha_string(&exhash, hostkeydata, hostkeylen);
2039 sha_mpint(&exhash, e);
2040 sha_mpint(&exhash, f);
2041 sha_mpint(&exhash, K);
2042 SHA_Final(&exhash, exchange_hash);
2043
7cca0d81 2044#if 0
e5574168 2045 debug(("Exchange hash is:\r\n"));
2046 for (i = 0; i < 20; i++)
2047 debug((" %02x", exchange_hash[i]));
2048 debug(("\r\n"));
7cca0d81 2049#endif
2050
2051 hostkey->setkey(hostkeydata, hostkeylen);
8d5de777 2052 if (!hostkey->verifysig(sigdata, siglen, exchange_hash, 20)) {
2053 bombout(("Server failed host key check"));
2054 crReturn(0);
2055 }
e5574168 2056
2057 /*
7cca0d81 2058 * Expect SSH2_MSG_NEWKEYS from server.
d39f364a 2059 */
7cca0d81 2060 crWaitUntil(ispkt);
8d5de777 2061 if (pktin.type != SSH2_MSG_NEWKEYS) {
2062 bombout(("expected new-keys packet from server"));
2063 crReturn(0);
2064 }
d39f364a 2065
2066 /*
7cca0d81 2067 * Authenticate remote host: verify host key. (We've already
2068 * checked the signature of the exchange hash.)
e5574168 2069 */
7cca0d81 2070 keystr = hostkey->fmtkey();
d5859615 2071 fingerprint = hostkey->fingerprint();
d4857987 2072 verify_ssh_host_key(savedhost, savedport, hostkey->keytype,
2073 keystr, fingerprint);
d5859615 2074 logevent("Host key fingerprint is:");
2075 logevent(fingerprint);
2076 free(fingerprint);
7cca0d81 2077 free(keystr);
d39f364a 2078
2079 /*
7cca0d81 2080 * Send SSH2_MSG_NEWKEYS.
d39f364a 2081 */
2082 ssh2_pkt_init(SSH2_MSG_NEWKEYS);
2083 ssh2_pkt_send();
d39f364a 2084
2085 /*
2086 * Create and initialise session keys.
2087 */
2088 cscipher = cscipher_tobe;
2089 sccipher = sccipher_tobe;
2090 csmac = csmac_tobe;
2091 scmac = scmac_tobe;
2092 cscomp = cscomp_tobe;
2093 sccomp = sccomp_tobe;
2094 /*
2095 * Set IVs after keys.
2096 */
2097 ssh2_mkkey(K, exchange_hash, 'C', keyspace); cscipher->setcskey(keyspace);
2098 ssh2_mkkey(K, exchange_hash, 'D', keyspace); cscipher->setsckey(keyspace);
2099 ssh2_mkkey(K, exchange_hash, 'A', keyspace); cscipher->setcsiv(keyspace);
2100 ssh2_mkkey(K, exchange_hash, 'B', keyspace); sccipher->setsciv(keyspace);
2101 ssh2_mkkey(K, exchange_hash, 'E', keyspace); csmac->setcskey(keyspace);
2102 ssh2_mkkey(K, exchange_hash, 'F', keyspace); scmac->setsckey(keyspace);
2103
033b4cef 2104 /*
7cca0d81 2105 * Now we're encrypting. Begin returning 1 to the protocol main
2106 * function so that other things can run on top of the
2107 * transport. If we ever see a KEXINIT, we must go back to the
2108 * start.
033b4cef 2109 */
7cca0d81 2110 do {
2111 crReturn(1);
2112 } while (!(ispkt && pktin.type == SSH2_MSG_KEXINIT));
2113 goto begin_key_exchange;
e5574168 2114
2115 crFinish(1);
2116}
2117
7cca0d81 2118/*
2119 * Handle the SSH2 userauth and connection layers.
2120 */
2121static void do_ssh2_authconn(unsigned char *in, int inlen, int ispkt)
2122{
7cca0d81 2123 static unsigned long remote_winsize;
2124 static unsigned long remote_maxpkt;
2125
e5574168 2126 crBegin;
2127
7cca0d81 2128 /*
2129 * Request userauth protocol, and await a response to it.
2130 */
2131 ssh2_pkt_init(SSH2_MSG_SERVICE_REQUEST);
2132 ssh2_pkt_addstring("ssh-userauth");
2133 ssh2_pkt_send();
2134 crWaitUntilV(ispkt);
8d5de777 2135 if (pktin.type != SSH2_MSG_SERVICE_ACCEPT) {
2136 bombout(("Server refused user authentication protocol"));
2137 crReturnV;
2138 }
7cca0d81 2139
2140 /*
2141 * FIXME: currently we support only password authentication.
2142 * (This places us technically in violation of the SSH2 spec.
2143 * We must fix this.)
2144 */
2145 while (1) {
2146 /*
2147 * Get a username and a password.
2148 */
2149 static char username[100];
2150 static char password[100];
2151 static int pos = 0;
2152 static char c;
e5574168 2153
67779be7 2154 if ((flags & FLAG_INTERACTIVE) && !*cfg.username) {
7cca0d81 2155 c_write("login as: ", 10);
67779be7 2156 ssh_send_ok = 1;
7cca0d81 2157 while (pos >= 0) {
2158 crWaitUntilV(!ispkt);
2159 while (inlen--) switch (c = *in++) {
2160 case 10: case 13:
2161 username[pos] = 0;
2162 pos = -1;
2163 break;
2164 case 8: case 127:
2165 if (pos > 0) {
2166 c_write("\b \b", 3);
2167 pos--;
2168 }
2169 break;
2170 case 21: case 27:
2171 while (pos > 0) {
2172 c_write("\b \b", 3);
2173 pos--;
2174 }
2175 break;
2176 case 3: case 4:
2177 random_save_seed();
2178 exit(0);
2179 break;
2180 default:
2181 if (((c >= ' ' && c <= '~') ||
2182 ((unsigned char)c >= 160)) && pos < 40) {
2183 username[pos++] = c;
2184 c_write(&c, 1);
2185 }
2186 break;
2187 }
2188 }
2189 c_write("\r\n", 2);
2190 username[strcspn(username, "\n\r")] = '\0';
2191 } else {
2192 char stuff[200];
2193 strncpy(username, cfg.username, 99);
2194 username[99] = '\0';
67779be7 2195 if ((flags & FLAG_VERBOSE) || (flags & FLAG_INTERACTIVE)) {
7cca0d81 2196 sprintf(stuff, "Using username \"%s\".\r\n", username);
2197 c_write(stuff, strlen(stuff));
2198 }
2199 }
2200
d8426c54 2201 if (ssh_get_password) {
7cca0d81 2202 char prompt[200];
b585ec46 2203 sprintf(prompt, "%.90s@%.90s's password: ", username, savedhost);
7cca0d81 2204 if (!ssh_get_password(prompt, password, sizeof(password))) {
2205 /*
2206 * get_password failed to get a password (for
2207 * example because one was supplied on the command
2208 * line which has already failed to work).
2209 * Terminate.
2210 */
2211 logevent("No more passwords to try");
2212 ssh_state = SSH_STATE_CLOSED;
2213 crReturnV;
2214 }
2215 } else {
2216 c_write("password: ", 10);
67779be7 2217 ssh_send_ok = 1;
7cca0d81 2218
2219 pos = 0;
2220 while (pos >= 0) {
2221 crWaitUntilV(!ispkt);
2222 while (inlen--) switch (c = *in++) {
2223 case 10: case 13:
2224 password[pos] = 0;
2225 pos = -1;
2226 break;
2227 case 8: case 127:
2228 if (pos > 0)
2229 pos--;
2230 break;
2231 case 21: case 27:
2232 pos = 0;
2233 break;
2234 case 3: case 4:
2235 random_save_seed();
2236 exit(0);
2237 break;
2238 default:
2239 if (((c >= ' ' && c <= '~') ||
2240 ((unsigned char)c >= 160)) && pos < 40)
2241 password[pos++] = c;
2242 break;
2243 }
2244 }
2245 c_write("\r\n", 2);
2246 }
2247
2248 ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
2249 ssh2_pkt_addstring(username);
2250 ssh2_pkt_addstring("ssh-connection"); /* service requested */
2251 ssh2_pkt_addstring("password");
2252 ssh2_pkt_addbool(FALSE);
2253 ssh2_pkt_addstring(password);
2254 ssh2_pkt_send();
2255
2256 crWaitUntilV(ispkt);
2257 if (pktin.type != SSH2_MSG_USERAUTH_SUCCESS) {
2258 c_write("Access denied\r\n", 15);
2259 logevent("Authentication refused");
2260 } else
2261 break;
2262 }
2263
2264 /*
2265 * Now we're authenticated for the connection protocol. The
2266 * connection protocol will automatically have started at this
2267 * point; there's no need to send SERVICE_REQUEST.
2268 */
2269
2270 /*
2271 * So now create a channel with a session in it.
2272 */
d211621f 2273 mainchan = malloc(sizeof(struct ssh_channel));
2274 mainchan->localid = 100; /* as good as any */
7cca0d81 2275 ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
2276 ssh2_pkt_addstring("session");
d211621f 2277 ssh2_pkt_adduint32(mainchan->localid);
2278 ssh2_pkt_adduint32(0x7FFFFFFFUL); /* our window size */
2279 ssh2_pkt_adduint32(0x4000UL); /* our max pkt size */
7cca0d81 2280 ssh2_pkt_send();
2281 crWaitUntilV(ispkt);
2282 if (pktin.type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
8d5de777 2283 bombout(("Server refused to open a session"));
2284 crReturnV;
7cca0d81 2285 /* FIXME: error data comes back in FAILURE packet */
2286 }
d211621f 2287 if (ssh2_pkt_getuint32() != mainchan->localid) {
8d5de777 2288 bombout(("Server's channel confirmation cited wrong channel"));
2289 crReturnV;
7cca0d81 2290 }
d211621f 2291 mainchan->remoteid = ssh2_pkt_getuint32();
2292 mainchan->u.v2.remwindow = ssh2_pkt_getuint32();
2293 mainchan->u.v2.remmaxpkt = ssh2_pkt_getuint32();
2294 mainchan->u.v2.outbuffer = NULL;
2295 mainchan->u.v2.outbuflen = mainchan->u.v2.outbufsize = 0;
7cca0d81 2296 logevent("Opened channel for session");
2297
2298 /*
2299 * Now allocate a pty for the session.
2300 */
67779be7 2301 if (!cfg.nopty) {
2302 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
2303 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
2304 ssh2_pkt_addstring("pty-req");
2305 ssh2_pkt_addbool(1); /* want reply */
2306 ssh2_pkt_addstring(cfg.termtype);
2307 ssh2_pkt_adduint32(cols);
2308 ssh2_pkt_adduint32(rows);
2309 ssh2_pkt_adduint32(0); /* pixel width */
2310 ssh2_pkt_adduint32(0); /* pixel height */
2311 ssh2_pkt_addstring_start();
2312 ssh2_pkt_addstring_data("\0", 1);/* TTY_OP_END, no special options */
2313 ssh2_pkt_send();
7cca0d81 2314
67779be7 2315 do {
2316 crWaitUntilV(ispkt);
2317 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2318 /* FIXME: be able to handle other channels here */
2319 if (ssh2_pkt_getuint32() != mainchan->localid)
2320 continue; /* wrong channel */
2321 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2322 }
2323 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
7cca0d81 2324
67779be7 2325 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2326 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 2327 bombout(("Server got confused by pty request"));
2328 crReturnV;
67779be7 2329 }
2330 c_write("Server refused to allocate pty\r\n", 32);
2331 } else {
2332 logevent("Allocated pty");
7cca0d81 2333 }
7cca0d81 2334 }
2335
2336 /*
67779be7 2337 * Start a shell or a remote command.
7cca0d81 2338 */
2339 ssh2_pkt_init(SSH2_MSG_CHANNEL_REQUEST);
d211621f 2340 ssh2_pkt_adduint32(mainchan->remoteid); /* recipient channel */
67779be7 2341 if (*cfg.remote_cmd) {
2342 ssh2_pkt_addstring("exec");
2343 ssh2_pkt_addbool(1); /* want reply */
2344 ssh2_pkt_addstring(cfg.remote_cmd);
2345 } else {
2346 ssh2_pkt_addstring("shell");
2347 ssh2_pkt_addbool(1); /* want reply */
2348 }
7cca0d81 2349 ssh2_pkt_send();
d211621f 2350 do {
7cca0d81 2351 crWaitUntilV(ispkt);
d211621f 2352 if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
2353 /* FIXME: be able to handle other channels here */
2354 if (ssh2_pkt_getuint32() != mainchan->localid)
2355 continue; /* wrong channel */
2356 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2357 }
7cca0d81 2358 } while (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2359 if (pktin.type != SSH2_MSG_CHANNEL_SUCCESS) {
2360 if (pktin.type != SSH2_MSG_CHANNEL_FAILURE) {
8d5de777 2361 bombout(("Server got confused by shell/command request"));
2362 crReturnV;
7cca0d81 2363 }
8d5de777 2364 bombout(("Server refused to start a shell/command"));
2365 crReturnV;
7cca0d81 2366 } else {
8d5de777 2367 logevent("Started a shell/command");
7cca0d81 2368 }
2369
2370 /*
2371 * Transfer data!
2372 */
8ccc75b0 2373 ssh_send_ok = 1;
6f34e365 2374 begin_session();
7cca0d81 2375 while (1) {
d211621f 2376 static int try_send;
e5574168 2377 crReturnV;
d211621f 2378 try_send = FALSE;
7cca0d81 2379 if (ispkt) {
2380 if (pktin.type == SSH2_MSG_CHANNEL_DATA ||
2381 pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA) {
2382 char *data;
2383 int length;
d211621f 2384 /* FIXME: be able to handle other channels here */
2385 if (ssh2_pkt_getuint32() != mainchan->localid)
7cca0d81 2386 continue; /* wrong channel */
2387 if (pktin.type == SSH2_MSG_CHANNEL_EXTENDED_DATA &&
2388 ssh2_pkt_getuint32() != SSH2_EXTENDED_DATA_STDERR)
2389 continue; /* extended but not stderr */
2390 ssh2_pkt_getstring(&data, &length);
d211621f 2391 if (data) {
3bdaf79d 2392 c_writedata(data, length);
d211621f 2393 /*
2394 * Enlarge the window again at the remote side,
2395 * just in case it ever runs down and they fail
2396 * to send us any more data.
2397 */
2398 ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
2399 ssh2_pkt_adduint32(mainchan->remoteid);
2400 ssh2_pkt_adduint32(length);
2401 ssh2_pkt_send();
2402 }
7cca0d81 2403 } else if (pktin.type == SSH2_MSG_DISCONNECT) {
2404 ssh_state = SSH_STATE_CLOSED;
d211621f 2405 logevent("Received disconnect message");
7cca0d81 2406 } else if (pktin.type == SSH2_MSG_CHANNEL_REQUEST) {
2407 continue; /* exit status et al; ignore (FIXME?) */
d211621f 2408 } else if (pktin.type == SSH2_MSG_CHANNEL_EOF) {
2409 continue; /* remote sends EOF; ignore */
2410 } else if (pktin.type == SSH2_MSG_CHANNEL_CLOSE) {
2411 /* FIXME: be able to handle other channels here */
2412 if (ssh2_pkt_getuint32() != mainchan->localid)
2413 continue; /* wrong channel */
2414 ssh2_pkt_init(SSH2_MSG_CHANNEL_CLOSE);
2415 ssh2_pkt_adduint32(mainchan->remoteid);
2416 ssh2_pkt_send();
2417 /* FIXME: mark the channel as closed */
2418 if (1 /* FIXME: "all channels are closed" */) {
2419 logevent("All channels closed. Disconnecting");
2420 ssh2_pkt_init(SSH2_MSG_DISCONNECT);
2421 ssh2_pkt_send();
2422 }
2423 continue; /* remote sends close; ignore (FIXME) */
7cca0d81 2424 } else if (pktin.type == SSH2_MSG_CHANNEL_WINDOW_ADJUST) {
d211621f 2425 /* FIXME: be able to handle other channels here */
2426 if (ssh2_pkt_getuint32() != mainchan->localid)
2427 continue; /* wrong channel */
2428 mainchan->u.v2.remwindow += ssh2_pkt_getuint32();
2429 try_send = TRUE;
7cca0d81 2430 } else {
8d5de777 2431 bombout(("Strange packet received: type %d", pktin.type));
2432 crReturnV;
7cca0d81 2433 }
2434 } else {
d211621f 2435 /*
2436 * We have spare data. Add it to the channel buffer.
2437 */
2438 if (mainchan->u.v2.outbufsize <
2439 mainchan->u.v2.outbuflen + inlen) {
2440 mainchan->u.v2.outbufsize =
2441 mainchan->u.v2.outbuflen + inlen + 1024;
2442 mainchan->u.v2.outbuffer = srealloc(mainchan->u.v2.outbuffer,
2443 mainchan->u.v2.outbufsize);
2444 }
2445 memcpy(mainchan->u.v2.outbuffer + mainchan->u.v2.outbuflen,
2446 in, inlen);
2447 mainchan->u.v2.outbuflen += inlen;
2448 try_send = TRUE;
7cca0d81 2449 }
d211621f 2450 if (try_send) {
2451 /*
2452 * Try to send data on the channel if we can. (FIXME:
2453 * on _all_ channels.)
2454 */
2455 while (mainchan->u.v2.remwindow > 0 &&
2456 mainchan->u.v2.outbuflen > 0) {
2457 unsigned len = mainchan->u.v2.remwindow;
2458 if (len > mainchan->u.v2.outbuflen)
2459 len = mainchan->u.v2.outbuflen;
2460 if (len > mainchan->u.v2.remmaxpkt)
2461 len = mainchan->u.v2.remmaxpkt;
2462 ssh2_pkt_init(SSH2_MSG_CHANNEL_DATA);
2463 ssh2_pkt_adduint32(mainchan->remoteid);
2464 ssh2_pkt_addstring_start();
2465 ssh2_pkt_addstring_data(mainchan->u.v2.outbuffer, len);
2466 ssh2_pkt_send();
2467 mainchan->u.v2.outbuflen -= len;
2468 memmove(mainchan->u.v2.outbuffer, mainchan->u.v2.outbuffer+len,
2469 mainchan->u.v2.outbuflen);
2470 mainchan->u.v2.remwindow -= len;
2471 }
2472 }
e5574168 2473 }
2474
2475 crFinishV;
2476}
2477
2478/*
7cca0d81 2479 * Handle the top-level SSH2 protocol.
2480 */
2481static void ssh2_protocol(unsigned char *in, int inlen, int ispkt)
2482{
2483 if (do_ssh2_transport(in, inlen, ispkt) == 0)
2484 return;
2485 do_ssh2_authconn(in, inlen, ispkt);
2486}
2487
2488/*
374330e2 2489 * Called to set up the connection. Will arrange for WM_NETEVENT
2490 * messages to be passed to the specified window, whose window
2491 * procedure should then call telnet_msg().
2492 *
2493 * Returns an error message, or NULL on success.
374330e2 2494 */
2495static char *ssh_init (HWND hwnd, char *host, int port, char **realhost) {
fb09bf1c 2496 char *p;
8f203108 2497
2498#ifdef MSCRYPTOAPI
2499 if(crypto_startup() == 0)
2500 return "Microsoft high encryption pack not installed!";
2501#endif
374330e2 2502
fb09bf1c 2503 p = connect_to_host(host, port, realhost);
2504 if (p != NULL)
2505 return p;
374330e2 2506
2507 if (!do_ssh_init())
2508 return "Protocol initialisation error";
2509
4017be6d 2510 if (hwnd && WSAAsyncSelect (s, hwnd, WM_NETEVENT, FD_READ | FD_CLOSE) == SOCKET_ERROR)
374330e2 2511 switch (WSAGetLastError()) {
2512 case WSAENETDOWN: return "Network is down";
2513 default: return "WSAAsyncSelect(): unknown error";
2514 }
2515
2516 return NULL;
2517}
2518
2519/*
2520 * Process a WM_NETEVENT message. Will return 0 if the connection
2521 * has closed, or <0 for a socket error.
2522 */
2523static int ssh_msg (WPARAM wParam, LPARAM lParam) {
2524 int ret;
2525 char buf[256];
2526
8ce72d2c 2527 /*
2528 * Because reading less than the whole of the available pending
2529 * data can generate an FD_READ event, we need to allow for the
2530 * possibility that FD_READ may arrive with FD_CLOSE already in
2531 * the queue; so it's possible that we can get here even with s
2532 * invalid. If so, we return 1 and don't worry about it.
2533 */
2534 if (s == INVALID_SOCKET)
2535 return 1;
374330e2 2536
8d5de777 2537 if (WSAGETSELECTERROR(lParam) != 0) {
2538 closesocket(s);
2539 s = INVALID_SOCKET;
374330e2 2540 return -WSAGETSELECTERROR(lParam);
8d5de777 2541 }
374330e2 2542
2543 switch (WSAGETSELECTEVENT(lParam)) {
2544 case FD_READ:
8ce72d2c 2545 case FD_CLOSE:
374330e2 2546 ret = recv(s, buf, sizeof(buf), 0);
2547 if (ret < 0 && WSAGetLastError() == WSAEWOULDBLOCK)
2548 return 1;
8d5de777 2549 if (ret < 0) { /* any _other_ error */
2550 closesocket(s);
2551 s = INVALID_SOCKET;
374330e2 2552 return -10000-WSAGetLastError();
8d5de777 2553 }
374330e2 2554 if (ret == 0) {
2555 s = INVALID_SOCKET;
8ce72d2c 2556 return 0;
374330e2 2557 }
2558 ssh_gotdata (buf, ret);
85ee8208 2559 if (ssh_state == SSH_STATE_CLOSED) {
2560 closesocket(s);
2561 s = INVALID_SOCKET;
2562 return 0;
2563 }
374330e2 2564 return 1;
374330e2 2565 }
2566 return 1; /* shouldn't happen, but WTF */
2567}
2568
2569/*
2570 * Called to send data down the Telnet connection.
2571 */
2572static void ssh_send (char *buf, int len) {
2573 if (s == INVALID_SOCKET)
2574 return;
2575
2576 ssh_protocol(buf, len, 0);
2577}
2578
2579/*
2580 * Called to set the size of the window from Telnet's POV.
2581 */
2582static void ssh_size(void) {
2583 switch (ssh_state) {
2584 case SSH_STATE_BEFORE_SIZE:
21248260 2585 case SSH_STATE_CLOSED:
374330e2 2586 break; /* do nothing */
2587 case SSH_STATE_INTERMED:
2588 size_needed = TRUE; /* buffer for later */
2589 break;
2590 case SSH_STATE_SESSION:
fef97f43 2591 if (!cfg.nopty) {
e5574168 2592 send_packet(SSH1_CMSG_WINDOW_SIZE,
fb09bf1c 2593 PKT_INT, rows, PKT_INT, cols,
2594 PKT_INT, 0, PKT_INT, 0, PKT_END);
fef97f43 2595 }
374330e2 2596 }
2597}
2598
2599/*
6abbf9e3 2600 * Send Telnet special codes. TS_EOF is useful for `plink', so you
2601 * can send an EOF and collect resulting output (e.g. `plink
2602 * hostname sort').
374330e2 2603 */
2604static void ssh_special (Telnet_Special code) {
6abbf9e3 2605 if (code == TS_EOF) {
67779be7 2606 if (ssh_version == 1) {
6abbf9e3 2607 send_packet(SSH1_CMSG_EOF, PKT_END);
2608 } else {
2609 ssh2_pkt_init(SSH2_MSG_CHANNEL_EOF);
d211621f 2610 ssh2_pkt_adduint32(mainchan->remoteid);
6abbf9e3 2611 ssh2_pkt_send();
2612 }
67779be7 2613 logevent("Sent EOF message");
ec55b220 2614 } else if (code == TS_PING) {
2615 if (ssh_version == 1) {
2616 send_packet(SSH1_MSG_IGNORE, PKT_STR, "", PKT_END);
2617 } else {
2618 ssh2_pkt_init(SSH2_MSG_IGNORE);
2619 ssh2_pkt_addstring_start();
2620 ssh2_pkt_send();
2621 }
6abbf9e3 2622 } else {
2623 /* do nothing */
2624 }
374330e2 2625}
2626
8ccc75b0 2627static SOCKET ssh_socket(void) { return s; }
2628
2629static int ssh_sendok(void) { return ssh_send_ok; }
fb09bf1c 2630
374330e2 2631Backend ssh_backend = {
2632 ssh_init,
2633 ssh_msg,
2634 ssh_send,
2635 ssh_size,
4017be6d 2636 ssh_special,
8ccc75b0 2637 ssh_socket,
97db3be4 2638 ssh_sendok,
2639 22
374330e2 2640};
Local modifications for Simon Tatham's `PuTTY' SSH client and terminal emulator